Ireland used to be a laggard in implementing modern fatherhood policies compared to its European neighbours. In 2016, it was one of the last EU countries to introduce paid paternity leave and three years later parental leave. These reforms indicate that Ireland is moving away from the US model of fatherhood to a social investment state closer to the Swedish model of shared parenthood. With the introduction of Paternity Benefit the Irish government aimed to achieve a take-up of about 46–61%, which is used as a yardstick to evaluate its success. First, this article assesses paternity leave take-up comprehensively through four different rates based on administrative and aggregate data. Overall, take-up had been increasing initially, but levelled already after four years at the lower government target. This is puzzling as countries with similar reforms reported a constant increase and higher take-up over time. Second, drivers for the low take-up are discussed. Specifically, occupational and class inequalities are key factors as only 55 percent of the male workforce have access to occupational top-ups in addition to the relatively low statutory benefit. Without increasing benefit generosity, take-up will stabilize at the rather modest levels in comparison to other European welfare states.