Antenatal care is one of the key preventive health services used around the world. In most Western countries, antenatal care traditionally involves a schedule of one-to-one visits with a care provider. A different way of providing antenatal care is through a group model. The first objective was to compare the effects of group antenatal care versus one-to-one care on outcomes for women and their babies. The primary outcomes were preterm birth (birth occurring before 37 completed gestational weeks), low birthweight (less than 2500 g), small-for-gestational age (less than the tenth percentile for gestation and gender) and perinatal mortality. Secondary outcomes included psychological measures and satisfaction as well as labour and birth and postnatal outcomes.The second objective was to compare the effects of group care versus one-to-one care on care provider satisfaction. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (9 March 2012), contacted experts in the field and reviewed the reference lists of retrieved studies. All identified published, unpublished and ongoing randomised and quasi-randomised controlled trials comparing group antenatal care with conventional antenatal care were included. Cluster-randomised trials were eligible for inclusion but none were identified. Cross-over trials were not eligible. Two review authors independently assessed studies for inclusion and evaluated trial quality. Two authors extracted data. Data were checked for accuracy. We included two studies (1369 women). There were no statistically significant differences between women who received group antenatal care compared with standard one-to-one care in relation to the primary outcomes. In particular, there was no difference in the rate of preterm birth rate between the two groups (risk ratio (RR) 0.87; 95% confidence interval (CI) 0.47 to 1.60; two trials; N = 1315) and the proportion of low birthweight (less than 2500 g) babies was similar between the groups (RR 1.03; 95% CI 0.73 to 1.46; two trials; N = 1315).Satisfaction was rated highly in women who were allocated to group antenatal care but only measured in one trial. In this trial, the mean satisfaction with care in group antenatal care was almost five times higher compared with those allocated to standard care (N = 993). A number of outcomes related to stress, distress and depression were reported in one trial. There were no differences between the groups in any of these outcomes.There were no data available on the effects of group antenatal care on care provider satisfaction. The available evidence suggests that group antenatal care is positively viewed by women with no adverse outcomes for themselves or their babies. This review is limited owing to the small number of studies/women and the majority of the analyses are based on a single study. More research is required to determine if group antenatal care is associated with significant benefits.