Socioeconomic status and social support have been identified as important determinants of several diseases and overall mortality, but these factors have not been adequately examined in relation to hip fracture risk. The aim of this study was to determine the relationship of socioeconomic status and marital status to hip fracture risk. We used data from a population-based case-control study in postmenopausal women aged 50-81 years during 1993-1995 who resided in six counties in Sweden. The analysis was based on 1327 incident cases of hip fracture and 3262 randomly selected controls. Socioeconomic and marital status were obtained by record linkage with census data in 1960, 1970, 1980 and 1990. Information on other possible risk factors for hip fracture was collected by a mailed questionnaire. Women who were gainfully employed in 1990 had an odds ratio (OR) of 0.74 [95% confidence interval (CI) 0.56-0.96] compared with those not gainfully employed; those in the highest tertile of household income had an OR of 0.74 (95% CI 0.60-0.90) compared with those in the lowest tertile of income. Women who lived in a one-family house had an OR of 0.85 (95% CI 0.72-0.99) compared with those living in an apartment. Divorced, widowed or unmarried women had a higher risk of hip fracture than married or cohabiting women; the OR was 1.40 (95% CI 1.06-1.85). Married women who were both gainfully employed and were living in a one-family house had a substantially decreased risk of hip fracture compared with unemployed women living without a partner in an apartment (OR 0.39; 95% CI 0.22-0.71). Occupational affiliation among women ever employed, and educational level, were not associated with hip fracture risk. We conclude that employment, household income, type of housing and marital status seem to be risk indicators of hip fracture risk independent of known osteoporotic risk factors.