Arriving in College Park for the 2002–03 season, Gilchrist had a freshman campaign as a backup to then-Terp guards Drew Nicholas and Steve Blake.
First, Gilchrist hit the game-winning free throw against a Chris Paul-led Wake Forest team, scoring 16 points and shooting 4-for-4 from 3-point range.
Gilchrist's ensuing foul shot would tie the game at 77 with 20 seconds left, and Maryland went on to dominate the overtime and secure a 95–87 victory.
With a middling 16–12 record, Maryland missed the NCAA tournament for the first time in 13 years and accepted a consolation trip to the NIT, where they lost in the semifinals to South Carolina.
In the summer of 2006 Gilchrist signed with the Euroleague French team Pau Orthez but was released shortly and moved back to Israel, to Ironi Naharia.
John Gilchrist played for the D-Fenders through March, then moved to the Idaho Stampede (another NBDL team) in April.
In August 2007 Gilchrist signed one-year contract with Latvian runners-up BK Ventspils, but in November 2007 was released.