In October 2017, it was confirmed that Van Graan would be leaving South Africa to join Irish Pro14 side Munster as their new head coach. He replaced outgoing Director of Rugby Rassie Erasmus, who was returning to South Africa. His first game with Munster was a 36–19 win away to Zebre in the Pro14 on 26 November 2017, although he officially took charge of the side the day after. He signed a two-year contract extension with Munster and the IRFU in April 2019, a deal that will see him remain with the province until at least June 2022.