Background. This study examines the effects of distress and three types of social relationships (family, friends, and confidantes) on the use of out-patient health services in an adult sample from a community survey of 3481 persons in Baltimore, Maryland.

Methods. Independent effects of predisposing (age, education, marital status, race and sex), enabling (employment, income and insurance) and need (physical health) factors are adjusted for in estimating the odds of using health care services.

Results. Illness, being female, and having insurance were positively related to use of services, while being aged was inversely related. After adjustment for the above factors, social support interacted with psychological distress to effect the use of medical care: the combination of high distress and low social support by a confidante results in a fourfold increase of medical utilization.

Conclusions. Our findings support the inclusion of psychological distress and social network variables in addition to physical health status in models attempting to explain the use of health services. Despite an inability to analyse change over time, our data suggest an understanding of the interrelationship between psychosocial factors, distress and health care use would benefit health providers and their patients.