In 36 hysterectomized women presenting with PMS, a daily record of eight mood states and five physical symptoms was kept during 109 ovarian cycles. Premenstrual tension (PMT) was estimated at a point 92% through the ovarian cycle after fitting a five-term Fourier series to the data. Although significant mood and physical-symptom swings were common (present in 71% and 69% of cycles respectively), the incidence of symptoms late in the luteal phase (PMT) was low (36%). In nine women no PMT was detected, in twenty-two women PMT was sporadic, and in five there was evidence of the consistent appearance of both mood and physical symptom-related PMT. Symptoms clustered significantly around a point 85% through the ovarian cycle for moods, and 83% for physical symptoms; this differs significantly from the 92% observed in menstruant women with PMS and is consistent with the removal of a factor associated with menstrual onset, which may contribute to the symptoms perceived by women as PMT.