After leaving university Forsyth was first elected to Westminster City Council from 1978 to 1983. He was then elected at the 1983 General Election as the MP for the Stirling constituency. His first job in government was as Parliamentary Private Secretary to the then Foreign Secretary Geoffrey Howe from 1986 to 1987. In 1987 he was appointed to the Scottish Office, first as an Under-Secretary of State (1987–90), then as Minister of State (1990–92) with responsibility over health, education, social work and sport. He was also the chair of the Scottish Conservative Party from 1989 to 1990. In 1996 he was named Parliamentarian of the Year.