318 social caseworkers (aged 29–65 yrs) participated in a longitudinal study designed to explore the relationships among life stress, possible "resistance" resources, and subsequent physical illness. Life stress was measured by the Recent Life Changes Questionnaire, while intra- and interpersonal traits and perceived community resources were measured using the Eysenck Personality Inventory, the State-Trait Anxiety Inventory, the Interpersonal Checklist, and portions of the Community Adaptation Schedule. After 10 mo, frequency of subsequent physical illness was measured by the Physical Health Status Questionnaire. Increased frequency of physical illness was associated with life changes in the work sphere and with greater hostility and inappropriate overreaction in interpersonal interactions. Findings suggest areas in which intervention could prevent stress and the resultant risk of physical disability. (17 ref)