Denial of pregnancy is an important condition that is more common than expected, with an incidence at 20 weeks gestation of approximately 1 in 475. The proportion of cases persisting until delivery is about 1 in 2500, a rate similar to that of eclampsia. Denial of pregnancy poses adverse consequences including psychological distress, unassisted delivery and neonaticide. It is difficult to predict which women will develop denial of pregnancy. There are a number of forms of denial of pregnancy, including psychotic and non-psychotic variants. Denial of pregnancy is a 'red flag' that should trigger referral for psychiatric assessment. A national registry may help to provide more information about this condition and implement appropriate care. This condition poses challenging legal and ethical issues including assessment of maternal capacity, evaluation of maternal (and possibly fetal) best interests and the possibility of detention in hospital.