Romero was traded by the Brewers to the Boston Red Sox in December 1985 in exchange for pitcher Mark Clear. Romero spent part of four seasons with the Red Sox (1986–1989), appearing in 219 games while batting .241 with two home runs and 42 RBIs. Boston release him in August 1989. While with Boston, he appeared in one game of the 1986 American League Championship Series, three games of the 1986 World Series, and one game of the 1988 American League Championship Series, going hitless in five at bats during those games.