Collins was elected to the Legislative Assembly at the 1976 state election, winning the new seat of Noble Park. A somewhat outspoken MP, he was a staunch opponent of massage parlors and had a strong interest in consumer affairs issues. He crossed the floor to vote with the National Party and Labor opposition in 1978 over a lack of parliamentary time set aside for discussing social welfare legislation. He was re-elected at the 1979 election. Collins had been floated as a potential minister during his second term, and when Lindsay Thompson ousted Rupert Hamer as Liberal leader and Premier in 1981, Thompson promoted Collins to cabinet secretary. In 1981, he travelled to Italy to locate any victims of the 1980 Irpinia earthquake who may have had family in Australia.