Smith was Called to the Bar by the Inner Temple in 1958. He served as a Flying Officer in the RAF from 1958 to 1960, then returned to his legal career. He was founder and Chairman of the Birmingham Free Representation Scheme. He was made a QC in 1977 and appointed as a Recorder. He was made a Bencher in 1985.
Smith was Liberal candidate for the Northampton division at the 1959 General Election. The constituency was a Labour/Conservative marginal and the Liberals had not run a candidate since coming a poor third in 1950. His prospects were not good and the party did not improve on its position.