The 37-year-old was released by the Braves on Sunday.
Jose Bautista signed a one-year contract with the Mets on Tuesday and started contributing right away in New York's game against the Marlins.
He started in left field, and batted fifth.
Bautista finished with one run and a double to his name.
The team announced earlier Tuesday he would be available for the game.
The 37-year-old was released by the Braves on Sunday. Bautista signed a minor league deal with the Braves last month after going unsigned in the offseason.
The six-time All-Star hit .143 with two home runs, five RBI and 12 strikeouts in 12 games for the Braves.
New York's Phillip Evans was optioned to Las Vegas to make room for Bautista.
The Mets (24-20) are a three and a half games behind the first-place Braves.