BACKGROUND: This retrospective chart review study describes on-site psychiatric consultations at a large, urban community primary care center. The referral population, diagnostic reliability of primary care providers (PCPs) and social workers, appropriateness of PCP-initiated treatment, impact of treatment recommendations, and outcomes are examined. METHOD: Charts of all patients who received psychiatric consultations (N = 78) during an 8-month period (August 1996 to April 1997) were reviewed. RESULTS: Prereferral diagnoses by PCPs matched the psychiatrist's diagnosis based on DSM-IV diagnostic criteria approximately half the time. PCPs initiated psychopharmacology in half the referrals (39/78) and used generally appropriate medications (30/39) based on diagnosis by a psychiatrist, but at subtherapeutic doses (21/39). PCPs tended to continue medications recommended by the psychiatrist. At 1 year, PCPs clearly documented improvement in nearly a third of the consults (24/78). CONCLUSION: Diagnostic disagreement of caregivers, inadequate PCP psychopharmacology practices, and patient nonadherence are 3 main problems that impede optimal care within the model of psychiatric consultation described in this study.