Washington played for the Royals from 1977 through 1984. His best offensive season was 1982, when he batted .286 with 10 home runs and 60 RBIs – all career highs. Washington was on first base and scored on George Brett's "pine tar" home run in 1983. In his eight seasons with the Royals, Washington hit .254 with 26 home runs and 228 RBIs. He was in four postseason series with the Royals — the 1980 ALCS, 1980 World Series, 1981 ALDS, and 1984 ALCS — batting 12-for-43 (.279) overall.