Jim Cashman was born in Blackrock in Cork City in 1965. The name Cashman had long been synonymous with Corkhurling as his father, Mick Cashman, played on the senior team in the 1950s and 1960s and was a stalwart for Munster in Railway Cup games. Cashman's uncle, Jimmy Brohan, was also a famed inter-county hurler. He played with Cork in the 1950s an 1960s and, in spite of never winning an All-Ireland medal, is regarded as one of the all-time greats of the game. Other relatives also had sporting success in various codes, including soccer and camogie. Jim's brother, Tom Cashman, also played with the Cork senior hurlers in the 1970s and 1980s.
Cashman made his debut on the Cork senior hurling team in the autumn of 1985 and won his first Munster title the following summer. He later collected his first All-Ireland medal as Cork, who were underdogs, defeated Galway in the championship decider. Over the next few years Tipperary re-emerged as the kingpins of Munster hurling, however, Cork were back in 1990 and, against all the odds, they claimed the Munster Championship title. Cashman later won a second All-Ireland medal after defeating Galway in a classic final. His performance in the championship earned him his first All-Star award. In 1991 Cork surrendered their Munster crown to Tipperary in dramatic fashion, however, in spite of this loss Cashman’s performance once again earned him an All-Star award. Cashman won a third Munster title in 1992 and once again qualified for the All-Ireland final. Unfortunately, Kilkenny ended up as the victors on that occasion. 1993 saw Cashman win a National Hurling League title, however, Cork’s championship form took another downturn. Cashman retired from inter-county hurling in 1996.