Fracture of the distal forearm is one of the most frequent osteoporotic fractures. However, there are few data concerning its incidence in Britain. The aim of this study was to determine the incidence of distal forearm fracture in adult British men and women. Six centers took part in the study: Aberdeen, Hull, Nottingham, Portsmouth, Southampton and Truro. At each center, men and women aged 35 years and over with an incident distal forearm fracture and who resided in the catchment area of the main hospital at that center, were identified during a 12 month period. Incident fractures were identified from all possible point-of-contact sources in each locality, including accident and emergency records, fracture clinics, ward listings and plaster room registers. The population at risk was defined geographically according to postcode and the denominator obtained from 1991 census data mapped to these postcodes. During the 12 month study period, 3161 individuals with distal forearm fracture were identified. The age-adjusted incidence, age 35 years and over, was 36.8/10,000 person-years in women and 9.0/10,000 person-years in men. In women, the incidence of fracture increased progressively with age from the perimenopausal period, while in men the incidence remained low until later life. Fractures were more frequently left-sided (55.6%) and 19.4% of subjects required hospitalization. On the basis of these data we estimate that 71,000 adult men and women sustain a distal forearm fracture in Britain each year. Compared with previous British surveys the pattern of incidence with age appears to have changed in women, the reason for this is unclear.