Objective: Taste is a hereditary trait and affects eating and dietary behavior. The tongue's papillae represent the first line of the gustatory apparatus to provide information about taste. The aim of the present investigation was to evaluate the number of fungiform papillae (fPap) in relationship with 6-n-propylthiouracil (PROP) sensitivity and body mass index (BMI) in patients with eating disorders. Methods: 18 female patients with eating disorders (anorexia or bulimia nervosa; age 14-20 yrs.) and 15 age-matched female controls were included. The number of fPap was quantified. Bitter taste was probed with PROP. Different BMIs (e.g. minimal BMI, maximal BMI) were calculated. Results: As regards non-tasters (PROP negative), anorectic patients showed a significant reduction in the number of fPap compared to both PROP negative healthy controls and also bulimic patients. The number of fPap did not differ significantly between tasters and non-tasters within controls and eating disorder groups. There was a trend of higher BMI's in bulimic and healthy non-tasters. Conclusions: In anorectic patients a reduced number of fPap was associated with a decreased PROP sensitivity, which is a new finding. The data of the present study support the notion that the variation of fPap number and PROP sensitivity influences the pathophysiology of eating behavior and taste perception, and following this are involved in the development of eating disorders.