Hidradenitis suppurativa (HS) is a common inflammatory skin disease. Medical treatment is often disappointing and in severe disease surgery remains the therapy of choice. Extensive surgery may be effective but also mutilating. Patients experience a significant reduction in quality of life and the need for new treatment modalities are urgent. In recent years patients with HS have been treated off-label with tumour necrosis factor-α (TNF-α) inhibitors with a varying degrees of effect. We performed a systematic review of papers retrieved from two databases (PubMed and Web of Science) using the following keywords: hidradenitis suppurativa, acne inversa, infliximab, etanercept, and adalimumab. A total of 34 publications were retrieved, describing treatment of 105 patients. Most cases report treatment with infliximab (52/105). A positive treatment outcome was reported in 90/105 cases, with only 7/105 non-responders and 8/105 patients experiencing side-effects. The side-effects were comparable to those seen in other TNF-α inhibitor studies. In the majority of cases the treatment was effective when given as a suppressive therapy, but 15/105 cases were described with long-term remission (≥3 months) after the end of therapy. In most publications follow-up was, however, insufficient to allow a systematic exploration of this. TNF-α inhibitors seem to be effective in the treatment of HS. However, several questions remain to be answered through specific studies. This review has also identified a need for more standardized reporting of the outcomes as well as randomized controlled trials in this disease.