Born in Clara, County Kilkenny, Prendergast first played competitive hurling during his schooling at St. Kieran's College. He arrived on the inter-county scene at the age of seventeen when he first linked up with the Kilkenny minor team before later joining the under-21 side. He made his senior debut during the 1978 championship. Prendergast immediately became a regular member of the team and won three All-Ireland medals, six Leinster medals, and three National Hurling League medals. He was an All-Ireland runner-up on two occasions.