OBJECTIVE The issue of leptin as a putative state marker of alcohol use and its role in craving has been raised in the last few years. Recently, a strong GABA-ergic modulation of leptin was postulated. The aim of the pilot study was to examine leptin levels in correlation with the strongly GABA-mimetic active substance clomethiazole. The main hypothesis was that higher doses of the strong GABA-mimetic clomethiazole are positively correlated with higher leptin levels. METHODS Twenty-eight alcohol-dependent patients (3 females, median age 36 years) undergoing alcohol withdrawal were included. In 18 patients with and 10 without clomethiazole, serum leptin was analyzed at day 1 and day 7 of alcohol withdrawal. Both groups did not differ by age, BMI, or alcohol use characteristics. RESULTS In the clomethiazole group, significant correlations were found between leptin levels at day 1 and clomethiazole dose (p = 0.004), clomethiazole and leptin at day 1/BMI (p = 0.009) and leptin at day 1 and clomethiazole/body surface (p = 0.006). Furthermore, patients with higher clomethiazole doses demonstrated significant higher leptin levels at day 1 (p = 0.044) and day 7 (p = 0.046). CONCLUSIONS Our pilot data show a strong association between leptin levels and clomethiazole doses, thus supporting further research.