Although LDS missionaries entered Italy around 1850, they soon left and Italy was not again assigned missionaries until the late 20th century. What follows here are some links that outline the history of the LDS Church in Italy.
LDS Church Granted Official Status
Rome Italy Temple is Landmark of Church Growth
First LDS Chapel in Italy
Church Statistical Summary for Italy (unofficial)
In 2010, the LDS Church News published a capsule of the history of the Church in Italy. The following is excerpted from that archived article:
"In southern Europe, jutting into the Mediterranean Sea, the boot-shaped Republic of Italy has a population that speaks Italian and is nearly all Roman Catholic.
"An early missionary area for the Apostles Peter and Paul, the first proselyting efforts in this dispensation began under the direction of Elder Lorenzo Snow of the Quorum of the Twelve Apostles. Arriving in Genova on the 25 June 1850, Elder Snow and his two companions, Thomas B. H. Stenhouse and Joseph Toronto, proceeded to the valleys of the Piedmont mountains in northeast Italy. Laboring among the Waldenses, a protestant religious group of French origin living in the area, the missionaries participated in the healing of three-year old Joseph Guy, opening the door for their missionary efforts. High in the Italian Alps above the city of La Tour (now known as Torre Pellice), Elder Snow dedicated the country for the preaching of the gospel on 19 September 1850, renaming the location Mount Brigham.
"Missionary work progressed with Elder Snow baptizing the first convert, Jean Antoine Bosc (also spelled Bose, Bos, and Box), at La Tour on 27 October 1850. The same year he also published the missionary tract, The Voice of Joseph, and two years later, the Book of Mormon in Italian. The missionaries organized three branches of the Church in the Piedmont area, Angrogne, St. Germain, and St. Bartholomew, baptizing a total of 221 people in the region between 1850 and 1854.
"Local opposition to the new faith and encouragement from Utah to gather west caused many of these early converts to immigrate to America. Conversions slowing, the missionaries shifted their efforts to Switzerland. By 1862, all active proselyting in the country stopped, with the mission officially closed in 1867. Daniel B. Hill Richards, serving in the Swiss mission, tried to re-open the work in 1900, but was refused legal permission.
"A Church presence, brought by foreign servicemen, finally returned to Italy during World War II. Five LDS chaplains served nearly 2,000 LDS military personnel in the region during the mid-1940s, organizing branches, performing ordinances, counseling and corresponding with family and friends. From that time onward there has been a continued LDS military presence in the country.
"Following the war, a permanent presence among Italians was established by the first converts. Vincenzo di Francesca, his story later portrayed in the 1987 Church film How Rare a Possession: The Book of Mormon, became the first modern Italian convert when he was baptized off the coast of Sicily by President Samuel E. Bringhurst of the Swiss-Austrian Mission on 18 January 1951.
"Other native Italians, like Pietro and Felicita Snaidero, found the Church while living in France, Germany or Switzerland during the 1950s. Taught the gospel by Italian speaking missionaries, these early converts returned to Italy and joined LDS servicemen stationed in the country in organizing the first branch in Naples on 28 April 1963 under the direction of the Swiss Mission. By 1964, when the Church republished the Book of Mormon in Italian, Church records showed 229 Latter-day Saints living in Italy. Among them were recent converts Leopoldo and Maria Larcher, who later served in their native Italy as mission president and regional representative.
"The presence of these early members led Elder Ezra Taft Benson of the Quorum of the Twelve Apostles to seek and receive permission from the Italian government for missionaries to enter the country. Missionary work formally began again in Italy on 27 February 1965 when President John M. Russon sent 20 Italian speaking missionaries from the Swiss Mission to the newly created Italian zone. Laboring in Turin, Milan, Brescia, Verona, Vicenza, Pordenone, Como and Varese, these elders prepared the way for the creation of the Italian Mission formed on 2 August 1966 by Ezra Taft Benson. Three months later, on 10 November, Elder Benson returned to Torre Pellice and Mount Brigham and blessed the country.
"With the formal organization of the mission, the Church grew in Italy. Five years after the mission was formed, it was split into the Italy North and Italy South Missions on 11 July 1971. A mission in Padova was opened in 1975 (closed and opened several times in later years). Also a mission was opened in Catania in 1977. Total Church membership passed 7,000 in 1978.
"Highlighting this decade of growth were visits by President Harold B. Lee in September of 1972 and President Spencer W. Kimball later in August of 1977. These visits marked the first to Italy by presidents of the Church since the Apostle Peter in the first Century.
"As the Church grew in Italy, so did its priesthood organization. The first stake was formed in Milan on 7 June 1981 with Mario Vaira as president. A second, the Venice Italy Stake, was created on 15 September 1985 with Claudio E. Luttmann as president. More recently, the Puglia Stake was organized on 9 March 1997 with Giovanni Carlo DiCarlo as president. Membership continued to grow, rising to over 14,000 by 1990.
"As membership increased, so did public notoriety. After years of lobbying, the Church gained legal status in the country when Italian President Oscar Luigi Scalfaro signed the legislation on 22 February 1993. The act allowed the Church to formally own property and its ministers to perform government-recognized marriages.
"In 1999, Elder Dieter F. Uchtdorf, president of the Europe West Area, met with President Scalfaro, thanking him and presenting him with a leather-bound copy of the Book of Mormon and a porcelain statue of a family. BYU and Ricks College groups (now BYU-Idaho) have also visited the area, performing to national audiences. They also participated with local members in commemorating the Pioneer sesquicentennial in July of 1997 by parading handcarts around the historic streets of Rome. The Mormon Tabernacle Choir visited in June of 1998, performing in Turin and later in Rome. Beginning in 2000, periodic national television programs have focused attention on the Church and its organizations, including programs on doctrine as well as the Primary and family history programs.
"In 2005, membership reached 21,791."
In 2010, the Italy Catania Mission was folded into the Italy Rome Mission and the boundary between it and the Italy Milan Mission to the north was altered to equalize the missions. Currently there are two missions in Italy: Italy Milan and Italy Rome.
As of today, there are 25.453 members of the LDS Church in Italy. They are organized into 103 local congregations (branches and wards), and 10 stakes, with 4 stakes in the Italy Rome Mission area and the remaining 6 in the Italy Milan Mission area.