INTRODUCTION: Tumor necrosis factor-alpha inhibitor (anti-TNF-α) agents are essential in treating inflammatory bowel diseases (IBD). Their use, however, may cause dermatoses. This study aims to characterize the dermatoses in IBD patients on anti-TNF-α therapy. METHODS: A total of 175 IBD patients, 105 (60%) on anti-TNF-α therapy were consecutively selected in a Brazilian referral center of gastroenterology and were evaluated by a dermatologist, regardless of whether they had dermatological complaints. RESULTS: The most prevalent disorders in patients receiving anti-TNF-α were skin infections (52.4%), unspecified alopecia not associated with psoriasiform eruptions (32.4%), seborrheic dermatitis (27.6%), infusion/injection reactions (14.5%), and psoriasiform eruptions (11.4%). The group not on anti-TNF-α treatment also presented a high prevalence of infection, seborrheic dermatitis, and alopecia, but no psoriasiform eruptions. There was a higher prevalence of dermatoses, when considered together, in patients taking anti-TNF-α. The use of these agents was independently associated with presence of dermatoses when grouped. CONCLUSION: The prevalence of dermatoses, considering together, was higher in the anti-TNF-α group. Infections, alopecia, seborrheic dermatitis, administration reactions, and psoriasiform eruptions were the most frequent dermatoses in patients taking anti-TNF-α.