A fine defensive infielder, Tim Cullen is best remembered for his days with the old Washington Senators during the late-1960s and early 1970s. He started playing in the minors in the pacific Coast League, 1964-66, prior to being called up to Washington DC in late-1966. In 1967 Tim Cullen hit .236 in 124 games, including 69 at shortstop. From the middle of 1968 thru 1972 he played mainly at the second base position. Traded to Oakland in 1972 he batted once in the ALCS and did not get a hit.

Tim Cullen played 498 games at second base, 180 at shortstop, 31 at third base and one game in the outfield.