Hidradenitis suppurativa (HS) is a chronic, relapsing, and debilitating inflammatory disease associated with profound morbidity. In this multicenter study, we investigated the demographic and clinical features of HS and determined risk factors of disease severity. A total of 1221 patients diagnosed with HS from 29 centers were enrolled, and the medical records of each patient were reviewed. The mean age of disease onset was 26.2 ± 10.4 years and almost 70% (n = 849) of patients were current or former smokers. Mean disease duration was 8.9 ± 8.4 years with a diagnosis delay of 5.8 ± 3.91 years. Twenty-one percent (n = 256) of patients had a family history of HS. The axillary, genital, and neck regions in males and the inframammary region in females were more frequently affected (p < 0.05 for all). Acne (40.8%), pilonidal sinus (23.6%), and diabetes mellitus (12.6%) were the most prevalent associated diseases.