After coming to hurling prominence as a student at CBS Kilkenny, Mulcahy won back-to-back All-Ireland Minor Championships with Kilkenny in 1935 and 1936. He was promoted to the Kilkenny junior side in 1938 and in the following year he won his first senior All-Ireland medal when Kilkenny beat Cork in the "thunder and lightning" final.[1][2] From 1939 onward Mulcahy was a regular on the senior team and struck up a forward partnership with Seánie O'Brien and Jim Langton. After losing back-to-back finals in 1945 and 1946, he claimed a second senior All-Ireland winners' medal after a defeat of Cork in one of the greatest finals of all in 1947.[3] Mulcahy played in his fifth All-Ireland final in 1950, lining out at full-forward against Tipperary, but Kilkenny were beaten by a point. He retired from inter-county hurling shortly after this, by which time he had also claimed seven Leinster Championships.
Mulcahy was the holder of four county senior championship medals with Éire Óg and had the distinction of winning county medals in four grades - minor, junior intermediate and senior - in the space of five years. As a referee, Mulcahy took charge of numerous games at club and inter-county level.
Later life and death
Mulcahy worked for some years in the Kilkenny Boot Factory before finding employment as a caretaker at the Kilkenny County Council offices. He died aged 43 on 26 April 1962 after suffering from colon cancer and was survived by his wife and three sons.[citation needed]