Antrim Over the last four decades McCarthy has been hugely interested in managing and coaching various teams at various levels all over the country. He first became involved in coaching in 1969 when he was recuperating following his motorcycle accident. During his time out from the playing McCarthy travelled to the opposite end of the country where he was invited to give coaching lessons to the
Antrim hurlers. He was hugely successful in this capacity as Antrim claimed the
All-Ireland title at intermediate level in 1970 following a convincing win over Warwickshire.
Cork (1975–1976) Not long after his retirement from playing McCarthy became fully involved in the management side of hurling. In 1975 he was appointed trainer of the Cork senior hurling team for the first time. In this regard he guided his native county to a Munster final victory over Limerick, the first of five provincial wins in-a-row. Cork were subsequently defeated by
Galway in the All-Ireland semi-final by just two points. Following this defeat McCarthy resigned as trainer.
Clare (1977–1980) Just before the start of 1977 McCarthy was approached by then manager
Fr. Harry Bohan to become his co-manager of the
Clare senior hurlers. McCarthy accepted the offer, a decision which came as a surprise to people in Cork. His first season in charge was a successful one from the beginning. Clare had had a good National League campaign and qualified for the final in 1977. Kilkenny, the reigning champions and victors over Clare in the final of 1976, provided the opposition on this occasion and an interesting game ensued. Clare's ability to get goals at crucial times proved vital and they claimed the 2–8 to 0–9 victory. With this victory under their belt Clare were widely tipped for success in the provincial championship. The team did reach the Munster final that year where McCarthy's native county of Cork provided the opposition. Clare got off to a really bad start when they conceded a penalty after seventy-five seconds which was duly converted by
Tim Crowley. Instead of crumbling Clare battled back and really put Cork to the pin of their collar. At half-time they trailed by only one point, however, they were reduced to fourteen men after
Jim Power was sent off. The second half was another interesting tussle, however, Cork won by 4–15 to 4–10. In 1978 Clare stormed through the National League again and qualified for the final for the third year in-a-row. Once again Kilkenny provided the opposition and, once again, an interesting game ensued. Clare's ability to get goals once proved the defining feature of a close game as McCarthy's side went on to win by 3–10 to 1–10. This victory buoyed up Clare for the provincial championship where they qualified for a second consecutive Munster showdown with Cork. Over 54,000 spectators turned up at
Semple Stadium that day to see Clare attempt to dethrone Cork. At half-time it looked as if Clare were about to triumph as they trailed by 0–5 to 0–3 after Cork recorded thirteen wides. With ten minutes left Cork led by five points, however, a late rally gave Clare some hope. At the full-time whistle Cork still had a narrow 0–13 to 0–11 win. This victory proved to be Clare's last chance of a championship breakthrough. McCarthy remained with the Clare hurlers until their exit from the championship in June 1980.
Cork (1984–1985) In 1984, McCarthy was back as joint-coach of the Cork senior hurling team with
the Rev. Michael O'Brien. It was the second time that he was coach of his native county. That year McCarthy helped guide Cork to their third Munster title in succession. The provincial final win over Tipperary was truly remarkable given the fact that Cork were trailing by four points with four minutes to go and ended up winning the game by four points. Cork beat Antrim in the semi final stage to advance to the centenary year All-Ireland final.
Offaly provided the opposition on that occasion in a special championship decider at
Semple Stadium in
Thurles. It was their first meeting in the history of the championship, however, Cork were the favourites. A 3–16 to 1–12 victory gave McCarthy's Cork a reasonably easy but a special victory nonetheless. In 1985 both McCarthy and O'Brien guided Cork to another Munster final appearance. Once again provincial rivals Tipperary stood in their way. The coaches had prepared their team well and a 4–17 to 4–11 victory was the result. The subsequent All-Ireland semi-final saw Cork take on Galway. McCarthy's side were the favourites going into the game, however, Galway had other ideas. A 4–12 to 5–5 defeat showed that the Cork team were far off the championship pace. This defeat was McCarthy's last championship in charge of the side and a new management team was installed at the end of the year.
Cashel King Cormac's Another challenge beckoned in 1990 when McCarthy took charge of the
Tipperary side
Cashel King Cormac's. It had been fifty years since the side had reached the final of the
Tipperary County Championship, however, in his first year in charge McCarthy steered them towards the final which they lost by one point. The following year they won the county championship before claiming the
Munster club title. McCarthy's side almost reached the All-Ireland club final, however, they were beaten by eventual winners
Kiltormer of
County Galway at the semi-final stage after playing two replays to decide the winner. McCarthy remained with Cashel until 1995. ==Managing Waterford==