BACKGROUND: Data on the epidemiology of reproductive-organ morbidity are needed to guide effective interventions, to set health-care priorities, and to target future research. This study aimed to find out the prevalence of reproductive-organ disease in a sample of rural Gambian women. METHODS: A questionnaire on reproductive health was administered by fieldworkers to women aged 15-54 years living in a rural area under demographic surveillance. A female gynaecologist questioned and examined the women (including speculum and bimanual pelvic examinations). Vaginal swabs were taken to test for Trichomonas vaginalis, Candida albicans, and bacterial vaginosis, cervical smears for cytology, cervical swabs for Chlamydia trachomatis PCR and Neisseria gonorrhoeae culture, and venous blood for haemoglobin, HIV, herpes simplex virus 2, and syphilis serology. FINDINGS: 1348 (72.0%) of 1871 eligible women took part. Reproductive-organ symptoms were more likely to be reported to the gynaecologist (52.7% of women) than to the fieldworker (26.5%). Menstrual problems, abnormal vaginal discharge, and vaginal itching were the most commonly reported symptoms. A minority of women said they had sought health care for their symptoms. The frequencies of reproductive-organ morbidity were high: menstrual dysfunction 34.1% (95% CI 29.6-39.1), infertility 9.8% (8.2-11.6), reproductive-tract infections 47.3% (43.7-51.0), pelvic tenderness 9.8% ((7.0-13.5), cervical dysplasia 6.7% (5.2-8.4), masses 15.9% (12.5-20.1), and childbirth-related damage to pelvic structures 46.1% (40.1-52.3). 948 (70.3%) women had at least one reproductive-organ disorder. INTERPRETATION: For these rural women, whose lives depend heavily on their reproductive function, reproductive-organ disease is a large burden. In inadequately resourced rural areas, with poor education, heavy agricultural and domestic labour, and limited access to quality health care, many women are not able to attain and maintain reproductive health and wellbeing.