Previous studies suggest that the ways in which parents respond to children's health complaints (reinforcement) and the ways in which they cope with their own illnesses (modeling) influence the frequency of symptoms, disability days, and health care visits made by these children when they grow up. However, previous studies have not controlled for the mediating influence of stress, neuroticism, and physical examination findings. This study investigated the influence of childhood social learning on adult illness behavior in 383 women aged 20 to 40 years. Illness behavior was measured prospectively for 12 months by the frequency of symptoms, disability days, and physician visits for menstrual, bowel, and cold (upper respiratory) symptoms. Childhood reinforcement and modeling was measured retrospectively by validated questionnaires. Other independent variables were stress, neuroticism, and selected demographic variables. Multiple regression analysis was used to assess the relative contribution of each independent variable to each category of illness behavior. The principal findings were as follows. First, childhood reinforcement of menstrual illness behavior significantly predicted adult menstrual symptoms and disability days, and childhood reinforcement of cold illness behavior significantly predicted adult cold symptoms and disability days. These effects were independent of stress and neuroticism. Second, childhood reinforcement scales were useful to predict which functional disorders (dysmenorrhea or irritable bowel syndrome) these subjects had even after we controlled for stress and neuroticism.