He was a right-handed batsman and a slow left-arm bowler who played for Kent. Aitchison made his debut for the Kent Second XI in the Minor Counties Championship competition of 1947, though he played just two games in his debut season. Aitchison did not play throughout 1948, but made his first-class debut just three days after his first Second XI appearance of 1949, playing against Glamorgan.
In his first match, he was given out leg before wicket in the first innings, but took three wickets with the ball in Glamorgan"s innings.
Aitchison played two further matches in his Kent career, in the 1950 season, and although the team finished in an improved ninth place in the County Championship table, Aitchison did not play again for the side.