Certolizumab-pegol is the first and only pegylated TNF-alpha antagonist approved in the treatment of Crohn's disease, rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis. We herein present a case of certolizumab-pegol induced generalized psoriasiform eruption in a patient with ankylosing spondylitis. The diagnosis was based on typical clinical and histopathological findings and further confirmed with Naranjo Adverse Drug Reaction Probability Scale which revealed a total score of nine supporting a definite causal relationship between the drug and skin eruption. As an important finding, a significant improvement of the generalized plaque lesions was achieved upon a therapy including high-potency topical corticosteroid and oral antihistamine without discontinuation of certolizumab-pegol. Moreover, we also present a literature review of the previously published cases with certolizumab-pegol induced psoriasiform eruption. Since all of these cases had Crohn's disease or rheumatoid arthritis as the underlying disease, this is the first case report of certolizumab-pegol induced psoriasiform eruption in a patient with ankylosing spondylitis, to the best of our knowledge.