My primary aim is to call into question an influential notion of paternal responsibility, namely, that fathers owe support to their children due to their causal responsibility for their existence. I argue that men who impregnate women unintentionally, and despite having taken preventative measures, do not owe child support to their children as a matter of justice; their children have no right against them to support. I argue for this on the basis of plausible principles of responsibility which have been (...) used to defend abortion rights. I then consider the morally relevant differences between men and women, arguing that while in some cases these differences may justify differential treatment, their import should not be overstated - in many cases, the burden of child support will be too great to impose justly on fathers. This conclusion is not as undesirable as it may seem: I suggest feminist considerations in favor of revising the notion of paternal responsibility and considering alternative arrangements of child support. (shrink)