The Mets purchased the contract of right-handed pitcher Tom Parsons from the Pittsburgh Pirates at the end of the 1964 season. He appeared in four games for the Mets during the month of September two as a starter and two out of the bullpen. He posted a 1-2 record with a 4.19 ERA. His one victory came on the last day of the season when he pitched 5 1/3 innings of relief in the Mets 15-5 victory over the St. Louis Cardinals
Parsons spent the entire 1965 season with the Mets splitting time between the starting rotation and the bullpen but posted a miserable 1-10 record with 4.67 ERA. His one victory was a complete game six hit shutout against the Chicago Cubs on July 5.
Following the season, the Mets traded Parsons to the Houston Astros for catcher Jerry Grote. In 39 appearances for the Mets Tom Parsons posted a 2 -12 record with 4.58 ERA.
While with the Mets Parsons wore number 27.
Tom Parsons also played for the Pittsburgh Pirates in 1963.