He was set apart as a missionary on September 7, 1891. He was assigned to serve with William B. Dougall, Jr., who was a grandson of Brigham Young. They were assigned to the 4 stakes that covered Juab, Millard, Beaver and Iron counties. The assignment was to increase attendance and participation in MIA, for both young men and young women. Smith and his new wife, Lucy, were missionaries in the church's Southern States Mission, with J. Golden Kimball as their mission president, from 1892 to 1894. Smith was appointed mission secretary. Initially when Smith left to serve in the Southern States mission on June 23, 1892, he left Lucy behind in Salt Lake City. Smith's first assignment in Tennessee was to serve in the Middle Tennessee District, covering the area in and around the city of Nashville. It was intended he would assume the position of mission secretary, essentially chief assistant to the mission president, in August. It was also planned for his wife to join him at that time. However, Kimball felt that Smith needed more training in the mission field before being joined by his wife, and so did not allow her to join her husband until November. From November 1892 to August 1893 and from October 1893 to May 1894 Kimball was out of the mission so Smith was acting mission president. As was common at the time, Smith was ordained a seventy when he went on his mission. After returning, he was made a member of the third quorum of the seventies presiding council in Salt Lake City, which meant he had specific assignments for conducting missionary outreach in the area. Smith also served as a Sunday School teacher and then as the organization's superintendent for the 17th Ward in Salt Lake City, immediately north-west of Temple Square. For a few years leading up to 1902 Smith served as an assistant to Richard R. Lyman and Joseph F. Merrill in running the Salt Lake Stake's youth program for young men. At the time the Salt Lake Stake took in all of Salt Lake county and was by far the largest stake by membership in the LDS Church. It was looked upon as the "flagship" stake of the church, and Lyman, Merrill and Smith initiated programs and changes that were adopted elsewhere throughout the church. Smith then served as head of the youth program for young men