BACKGROUND: Earlier studies have suggested a relationship between bipolar disorder (BP) and eating disorders (ED), more specifically, bulimia nervosa (BN) and bipolar II disorder (BP-II). In the present report we extend this relationship to broader definitions of bipolarity. METHODS: Semi-structured interview of 201 patients with DSM-IV criteria for major affective disorders combined with Akiskal and Mallya criteria for Affective temperaments. To diagnose lifetime comorbid eating disorders DSM-IV criteria for eating disorders (Bulimia Nervosa, BN, Anorexia, AN) were used. RESULTS: 33 patients had an eating disorder. When compared to patients without ED the patients with ED had a higher prevalence of bipolar disorders. Using strict DSM-IV criteria, this association was only significant for BN (OR) 4.5 (95% CI 1.1-17.6). When using a broader index of bipolarity including patients having affective temperaments, a significant relation was found for BN (OR) 9.1 (95% CI 1.1-73.6), and for patients with a lifetime history of both BN and AN (OR) 8.6 (95% CI 1.1-70.2).We also found patients with ED to have a significantly higher prevalence of affective temperaments, an earlier onset of major affective disorder and to have more depressive episodes. LIMITATIONS: Non-blind evaluation of diagnosis for mood, eating disorders and affective temperaments. CONCLUSION: In line with previous reports we describe an association between bulimia nervosa and bipolar disorder. Furthermore we report a relationship between lifetime bulimia and anorexia and cyclothymic and related affective temperaments.