In the 1983 American League Championship Series and the 1983 World Series, he pitched a combined innings over five games, did not give up any runs, struck out eight batters. He earned an ALCS save on October 7. He had been placed on 18 months probation the day before, stemming from a July arrest for driving while intoxicated. His attorney announced that Stewart was undergoing treatment for alcohol problems. He went 51–45 with 42 saves and a 3.47 ERA in eight seasons with the Orioles.