Apart from energy homeostasis leptin has been shown to be involved in a number of neuronal networks. The aim of this study was to investigate how the residual variance of leptin levels, after controlling for BMI, is linked to eating-disorder-specific psychopathology and sexual desire in patients with anorexia nervosa (AN) compared to healthy controls. The sample included 57 subjects with acute AN and 77 healthy controls. Psychopathology was determined by EDI-2 and SCL-90-R and sexual problems were rated according to the Structured Interview of Anorexia Nervosa and Bulimic Syndromes (SIAB-EX). Plasma leptin was assessed by ELISA. Patients with a high drive for thinness had lower leptin levels at a given BMI and low leptin levels were associated with sexual problems, i.e. the absence of sexual desire and intimate relationships. Our results are in accordance with recent animal experiments linking low leptin levels with decreased sexual interest irrespective of body weight.