 Mulcahy made his senior hurling championship debut for Cork on 26 June 1983 when he came on as a substitute in a 1–14 to 1–12 Munster semi-final replay defeat of Limerick.He was added to the starting fifteen at right corner-forward for the subsequent provincial decider against Waterford.Mulcahy scored a point and collected his first Munster medal following a huge 3–22 to 0–12 victory.