Objective: To examine DSM-IV lifetime/current psychiatric disorder co-morbidity and correlates in ethnically-diverse obese patients with binge eating disorder (BED) seeking treatment for obesity and binge eating in primary care. Method: A consecutive series of 142 participants (43% Caucasian, 37% African-American, 13% Hispanic-American, and 7% "other" ethnicity) were evaluated with semi-structured interviews. Results: 67% of BED patients had at least one additional lifetime psychiatric disorder, with mood (49%), anxiety (41%), and substance-use (22%) disorders most common. In terms of current co-morbidity, 37% had at least one other psychiatric disorder, with anxiety (27%) and mood (17%) most common. Few gender differences were observed but psychiatric co-morbidity rates differed across ethnic/racial groups with larger differences for current diagnoses. African-American and Hispanic groups were more than twice as likely as the Caucasian group to have additional current psychiatric disorders, mood disorders, and anxiety disorders. Psychiatric co-morbidity was associated with greater eating-disorder psychopathology and poorer functioning, but not with binge-eating or BMI. Conclusion: Our study presents new findings suggesting that among obese BED patients in primary care, ethnic/racial minority groups are more likely than Caucasian groups to present with psychiatric co-morbidity. Within BED, psychiatric co-morbidity shows few gender differences but is associated with greater eating-disorder psychopathology and poorer functioning.