In order to assess the prevalence of back pain problems among family care workers, and the association of back pain with selected variables, a cross-sectional survey among the 4723 employees of the largest Flemish organization for family care was conducted. A self-administered questionnaire comparable to the standardized Nordic questionnaire on musculoskeletal symptoms was distributed to all employees of the organization. The response rate was 90 per cent (n = 4256) and the study population was almost uniformly composed of females (99.8 per cent). The period prevalence (12 months) amounted to 63 per cent (95 per cent CI: 61.7-64.6) and the point prevalence to 18 per cent (95 per cent CI: 16.5-18.8). Among the respondents suffering from back pain during the past year, 72 per cent suffered from repeated episodes of pain. In 82 per cent low back pain was involved. Twenty-nine per cent of the complaints interrupted their work during the past year, yielding a total number of 23,396 days of sick leave. The mean sick leave for back pain was 36 days and the median 15 days. The frequency of back pain was found to vary according to the regional departments to which the employees belonged, some sections experiencing up to 36 per cent higher period prevalences than the units with the lowest figures.(ABSTRACT TRUNCATED AT 250 WORDS)