The value of gentle, unilateral breast stimulation in the ripening of cervix and induction of labour was studied. Three hundred patients with uncomplicated term pregnancies, (38-42 weeks) were recruited into the study, consisting of three separate randomised double blind prospective trials. The first trial was to evaluate the effectiveness of breast stimulation in ripening the cervices of 200 term primigravid patients. There was a mean change of 3.90 +/- 2.39 points in cervical score among the study group compared to 0.50 +/- 0.67 among the control group. Thirty-three per cent of the study group went into labour when compared with 4% among the control group. In a second study of cross-over trial involving 78 of the original 200 patients, the study (ex-control) group had a mean change in cervical score of 3.84 +/- 2.24 when compared with the control (ex-study) group, (1.43 +/- 1.08). In a third study involving 100 multiparous patients, a mean change in cervical score of 2.74 +/- 1.16 was observed in the study group when compared with the control group, 0.92 +/- 1.07. Forty-six per cent of the patients went into labour compared with 12% in the control group. All findings were highly significant and there were no maternal or fetal side-effects. The study confirmed the efficacy of breast stimulation in cervical ripening and induction of labour.