During the decade 1970-9, 23 002 infants born in the University of Bristol Department of Obstetrics were examined for congenital dislocation of the hip by junior members of the paediatric staff on the first day of life and again on discharge from hospital. Suspected hip abnormality was checked by a senior member of the staff on the same day. A total of 445 (1.9%) infants were found to have a hip abnormality in the neonatal period. Immediate treatment in an abduction splint was undertaken, usually six weeks for dislocatable hips and 12 weeks for dislocated hips. Routine follow up included clinical and radiological examination at six, 12, 24, and 60 months. Altogether 90% completed the 12 month, 85% the 24 month, and 76% the 60 month checks. Five infants (1.1%) required further orthopaedic treatment (adductor tenotomy and abduction splinting) but no major surgery was necessary, nor was avascular necrosis encountered. The radiological results were excellent. Every effort (1970-84) was also made to identify all cases of late congenital dislocation of the hip diagnosed after the neonatal period in infants born to women in Avon during the same decade (n = 103 431). Ninety one cases were detected (0.88 per 1000 births), 10 in the university cohort (0.44 per 1000) and 81 in the non-university group (1.00 per 1000) (P less than 0.01). Seven of 10 in the former group required open surgery and in seven the radiological outcome at follow up was moderate or poor. The early and late diagnosed groups are compared in respect of perinatal factors and management. It is possible to detect most cases of congenital dislocation of the hip at birth and treat them safely and successfully.