There are increasing numbers of people on long-term sick leave, especially with stress-related ill health and musculoskeletal disorders. The main purpose of this study is to, early on in the sick leave, find predictors of individual resources for a return to work. The study group consists of women and men on sick leave compared with reference groups of healthy persons. A questionnaire was used regarding diagnosis given on the doctor's certificate, self-reported symptoms, residential area, education, and kind of work. It also contained open questions about consequences in daily life and beliefs about future. Checklists concerning life satisfaction, sense of coherence, locus of control, coping resources and sick leave information over a four-year period have been used. Significant differences between the study group and the reference groups were found, relating to sense of coherence, locus of control, life satisfaction and coping resources. More than half of the study group were still on sick leave at a two-year follow-up. Important predictive factors turned out to be: previous sick leave, own belief about future and self-reported symptoms.