Seasonal variations in binging, purging, food preference and mood were investigated in patients with bulimia nervosa (BN) and in normal controls (NC) using a retrospective questionnaire, the Seasonal Pattern Assessment Questionnaire. Thirty one patients with BN and 31 nonbulimic NCs were matched on age and SES. Results indicated that binging, purging, total food preference and mood in BN exhibited strong relationships with seasonal changes in meteorological variables represented by photoperiod. In contrast, NCs experienced seasonal variations in mood but not in total food preference. Neither group experienced preferential seasonal changes in carbohydrate foods. SAD was more prevalent in BN than in NCs. Results suggest that BN is a disorder of satiety for calories rather than carbohydrates which varies seasonally and is accompanied by significant seasonal variations in mood. Results are discussed with respect to serotonergic functionning and the relationship between BN and SAD.