To compare the costs to the health service, women and their families of routine antenatal care provided by either traditional obstetrician-led shared care or general practitioner (GP)/community midwife care. A multicentre randomized controlled trial in 51 general practices linked to nine maternity hospitals in Scotland: 1667 low-risk pregnant women provided information on costs to the health service. 704 of these women provided information on non-health service costs. GP/midwife antenatal care was found to cost statistically significantly less than shared care. This was the case for investigations carried out at routine antenatal visits (GP/midwife = 87.25 Pounds, shared care = 91.15 Pounds, P = 0.05), staffing costs at routine antenatal visits (GP/midwife = 127.76 Pounds, shared care = 131.09 Pounds, P = 0.001), and non-health service costs incurred by women and their companions (GP/midwife = 118.53 Pounds, shared care = 133.49 Pounds, P = 0.001). While non-routine care in the GP/midwife arm of the trial costs less than in the shared care arm, the difference was not statistically significant (GP/midwife = 83.74 Pounds, shared care = 94.43 Pounds, P = 0.46). The total societal cost of antenatal care was 417.28 Pounds per women in the GP/midwife arm of the trial and 450.19 Pounds in the shared care arm of the trial. This difference was statistically significant (P < 0.001). The application of sensitivity analysis did not change these results. GP/midwife antenatal care is a satisfactory option for low-risk pregnant women in Scotland provided that clinical outcomes and women's satisfaction are at least the same as those of women with shared care.