Fisher's busiest seasons were with the early New York Mets. In four seasons (1964–1967) with the perennial losers he won 38 games, lost 73, and had an ERA of 4.58 in 931.2 innings pitched. (The Mets played .355 ball during this time.) Fisher led the National League twice in losses (1965 and 1967) and three times in earned runs allowed (1964, 1965, and 1967). In 1965 he lost 24 games, still tied with Roger Craig for the most since 1935. In 1967, however, Fisher pitched the lowest-hit complete game of his career, a two-hit shutout over the Philadelphia Phillies (June 21 at Connie Mack Stadium).