Aims and methodTo assess the impact in the South London and Maudsley NHS Foundation Trust of a 20-month quality improvement programme on adherence with National Institute for Health and Clinical Excellence (NICE) recommendations for the use of valproate for bipolar illness in women of childbearing potential.ResultsSignificant improvement was noted between baseline and final audit in rates of information provision (10% v. 63%, P < 0.0001), contraceptive use (15% v. 38%, P = 0.0003) and folate prescription (3% v. 35%, P < 0.0001).Clinical implicationsAdherence to guidance can be usefully improved by a sustained intervention programme.