OBJECTIVE--To compare routine antenatal care provided by general practitioners and midwives with obstetrician led shared care. DESIGN--Multicentre randomised controlled trial. SETTING--51 general practices linked to nine Scottish maternity hospitals. SUBJECTS--1765 women at low risk of antenatal complications. INTERVENTION--Routine antenatal care by general practitioners and midwives according to a care plan and protocols for managing complications. MAIN OUTCOME MEASURES--Comparisons of health service use, indicators of quality of care, and women's satisfaction. RESULTS--Continuity of care was improved for the general practitioner and midwife group as the number of carers was less (median 5 carers v 7 for shared care group, P<0.0001) and the number of routine visits reduced (10.9 v 11.7, P<0.0001). Fewer women in the general practitioner and midwife group had antenatal admissions (27% (222/834) v 32% (266/840), P<0.05), non-attendances (7% (57) v 11% (89), P<0.01) and daycare (12% (102) v 7% (139), P<0.05) but more were referred (49% (406) v 36% (305), P<0.0001). Rates of antenatal diagnoses did not differ except that fewer women in the general practitioner and midwife group had hypertensive disorders (pregnancy induced hypertension, 5% (37) v 8% (70), P<0.01) and fewer had labour induced (18% (149) v 24% (201), P<0.01). Few failures to comply with the care protocol occurred, but more Rhesus negative women in the general practitioner and midwife group did not have an appropriate antibody check (2.5% (20) v 0.4% (3), P<0.0001). Both groups expressed high satisfaction with care (68% (453/663) v 65% (430/656), P=0.5) and acceptability of allocated style of care (93% (618) v 94% (624), P=0.6). Access to hospital support before labour was similar (45% (302) v 48% (312) visited labour rooms before giving birth, P=0.6). CONCLUSION--Routine specialist visits for women initially at low risk of pregnancy complications offer little or no clinical or consumer benefit.