Gates made his debut for Ipswich Town as an eighteen-year-old on 27 October 1973 at Portman Road replacing Roger Osborne during a 2–0 victory against Wolverhampton Wanderers in front of a crowd of 20,882. Gates would make a further 16 substitute appearances before he made his full debut against Derby County at The Baseball Ground in October 1975. Gates' first goal as a professional footballer came later that month in a 3-0 UEFA Cup victory against FC Bruges at Portman Road in the 1st leg of the 2nd round. Highlights of Gates' time at Ipswich Town include both goals in a 2–1 over FC Barcelona at Portman Road in the first leg of the 1979 Cup Winners Cup quarter final. Gates contributed to Ipswich's victorious 1977-78 FA Cup campaign, making one appearance during the run against Cardiff City in the third round. However he wasn't part of the squad for the final itself. Gates' greatest moment was as part of the team that won the 1981 UEFA Cup Final against AZ Alkmaar, starting both legs of the final.