Using a two-stage case identification process, patients from a rural primary care practice were assessed for psychiatric disorders (Research Diagnostic Criteria [RDC] categories) over a 15-month period. The prevalence of all psychiatric disorders was 26.5%; 10.0% were specific RDC depressive disorders, and 5.3% were disorders without depression, usually anxiety related. Another 11.2% of patients were thought to have a disorder with significant depressive symptomatology that could not be classified into a specific depressive disorder category, a finding that suggests restricted usefulness of specialty-based categories for the range of clinical presentations in primary care. The relationship of demographic variables to specific disorders was examined; there were age, sex, and marital status differences in the rates for certain disorders, although these findings need replication using large patient samples. The prevalence findings emphasize the need for research on outcome and treatment response for depression presentations in primary care.