OBJECTIVE To describe the variability of reproductive life, from menarche to menopause, in the Geneva female population. DESIGN Women's Health Survey, 1992-1993. SETTING Mobile epidemiology unit of a University Hospital. SUBJECTS One thousand and thirty-two women aged 30 to 74 years, resident in Geneva, Switzerland. MAIN OUTCOME MEASURE Menstrual and reproductive history. RESULTS A 'typical' woman of Geneva has her menarche at 13 years, regular 28 day cycles with 5 days of menstrual flow. She is 26 years old when she first gives birth and has her last baby (which is typically the second) at age 31. She has 37 years of potential fecundity and a natural menopause at age 50. In addition, 11% of the women have tried to be pregnant during two years without success, 67% have ever used oral contraceptives, 20% had a first birth at age 30 or more and 23% were nulliparous. Younger women reported earlier ages at menarche. Women with lower education tended to be a younger age at the birth of her first child. CONCLUSIONS In this first study of the reproductive characteristics of women in Geneva, nulliparity and a late first birth appeared unusually frequent, especially when compared with American or Chinese women. The observed distributions of reproductive history are compatible with the very high incidence rate of breast cancer in the Geneva population.