Hidradenitis Suppurativa (HS) is a chronic inflammatory skin disease that affects the hair follicles in the axillary, perianal and inguinal area. Its cause and pathogenesis are unknown, but cigarette smoking increases the risk of developing HS conceivably by accumulating toxic metabolites in sweat. The xenobiotic compounds from tobacco are metabolized by the cytochromes P-450. The cytochrome P-450 1A1 (CYP1A1), one of the most active isoenzymes, harbours several polymorphisms. Two of them, MspI and Ile(462)Val single nucleotide polymorphism (SNP), are associated with enhanced activity and inducibility. Performing direct DNA sequencing, we investigated the frequencies of these SNP in 51 patients with HS, 45 of these were smokers. We found similar overall SNP rates in our patients in comparison with previous data for Caucasian or German controls. Obviously, there is no relation between the occurrence of these SNPs and the risk of developing HS.