This paper studies the impact of the introduction of joint custody in Italy (Law 54/2006) on judiciary outcomes. As to the formal (legal) assignment of joint custody, the reform envisaged very little judge discretion. With reference to the substance of the custody (the amount of time each parent spends with the child and the money involved in post-dissolution arrangements), the law established new principles while leaving plenty of implementation power to the judges. Our results – based on court data that covers the universe of separations from 2000 to 2010 – document that the law was only cosmetically applied by the judges. Compared to the prereform regime, the share of sole legal custody assignments to the mother drastically decreased. However, court implementation washed out the new principles: the provisions of the law related to the financial postseparation arrangements remained unapplied. This suggests that the main innovative aspect of the law – the possibility for a child to spend an adequate amount of time with both parents – was also left unchanged with respect to the previous regime of sole maternal custody. As joint effect of the introduction of the law and the little degree to which the new principles have been translated into actual verdicts, there was a surge in litigiousness among separating spouses and judicial inefficiency. Moreover, the incentives for a female partner to apply for a separation raised. The paper discusses a possible rationale for the findings and some related policy remedies. As for the former, the evidence we present can be explained by the adoption of genderbiased judiciary practices. As for the latter, our results suggest that a restatement of the law, to define a narrowed grid of prescriptions that constrain judge discretion, could be an effective corrective action.