OBJECTIVE As a gateway to the mental health system, psychiatric emergency services (PES) are charged with assessing a heterogeneous array of short-term and long-term psychiatric crises. However, few studies have examined factors associated with inpatient psychiatric hospitalization following PES in a racially diverse sample. We examine the demographic, service use and clinical factors associated with inpatient hospitalization and differences in predisposing factors by race and ethnicity. METHODS Three months of consecutive admissions to San Francisco's only 24-h PES (N = 1,305) were reviewed. Logistic regression was used to estimate the associations between demographic, service use, and clinical factors and inpatient psychiatric hospitalization. We then estimated separate models for Asians, Blacks, Latinos and Whites. RESULTS Clinical severity was a consistent predictor of hospitalization. However, age, gender, race/ethnicity, homelessness and employment status were all significant related to hospitalization. Alcohol and drug use were associated with lower probability of inpatient admission, however specific substances appear particularly salient for different racial/ethnic groups. CONCLUSIONS While clinical characteristics played an essential role in disposition decisions, these results point to the importance of factors external to PES. Individual and community factors that affect use of psychiatric emergency services merit additional focused attention.