To assess a policy of women holding and thus having constant access to their own obstetric records, 290 women attending a peripheral consultant clinic in Newbury, West Berkshire, were randomly allocated to hold either their full case notes, or the more usual co-operation card. Women holding their full records were significantly more likely to feel in control of their antenatal care (rate ratio 1.45; 95% confidence interval 1.08-1.95) and to feel it was easier to talk to doctors and midwives (rate ratio 1.73; 95% confidence interval 1.16-2.59). No other beneficial effects were detected. Asked about their preferences for any subsequent pregnancies, women holding their own records in the index pregnancy were more likely to say they would prefer to hold the same kind of record again in a subsequent pregnancy than were women holding a co-operation card (rate ratio 1.56; 95% confidence interval 1.34-1.81). There was no evidence of negative effects. In particular, women holding their case notes did not feel more anxious than co-operation card holders. The policy of women holding their notes resulted in savings in clerical time, without evidence of an increase in the rate of lost notes.