As a national cycling champion Pat Gellineau was selected to represent Trinidad and Tobago on both the road and track at the 1972 München Olympics. Gellineau competed in the road race and team time trial, finishing 29th in the latter, in addition to placing 20th in the team pursuit. After the Olympics he moved to New York City, where he became a US citizen. He was a regular at the velodrome in Trexlertown, Pennsylvania, competing in the Madison and points races. Gellineau continued to compete in age-graded races on the track, winning gold in the 50-54 age group at the 2003 US Masters Track Cycling Championships. He followed this with a silver in the 55-59 age group in the points race five years later at the same championships.