In spring training of the 1987 season, LaValliere was traded to the Pittsburgh Pirates alongside Andy Van Slyke and Mike Dunne in exchange for fellow catcher Tony Peña. LaValliere and Van Slyke later became stalwarts on the hugely successful Pirates teams of the early 1990s, when Pittsburgh went to three consecutive National League Championship Series from 1990 to 1992. Unfortunately for the Pirates, they lost in all three of their NLCS appearances, in 1990 to the eventual World champion Cincinnati Reds and in 1991 and 1992 to the Atlanta Braves. In the 1992 NLCS, LaValliere was involved in the famous final play of Game 7, as Atlanta first baseman (and former Pirate) Sid Bream slid and just barely beat LaValliere's tag to score the Series-winning run for the Braves.