AbstractAnti‐drug antibodies (ADAs) can form with certain biological medications, but their clinical significance is not fully understood. ADA formation in psoriasis patients treated with IL‐23 inhibitors was evaluated, looking at the incidence of ADAs, impact on clinical outcomes and association with adverse events. A systematic search of PubMed, Cochrane and Embase databases yielded 318 articles, which were manually reviewed. A total of 19 articles met the eligibility criteria. The incidence of ADAs with the IL‐23 inhibitors was as follows: 4.1–14.7% with guselkumab, 141–31% with risankizumab and 6.51–18% with tildrakizumab. The incidence of neutralizing antibodies ranged from 01–0.6% with guselkumab, 21–16% with risankizumab and 2.5 to 3.2% with tildrakizumab. There was no evidence of reduced efficacy of psoriasis treatment with ADA presence alone. However, some studies found a reduction in clinical response with high ADA titres or with the presence of neutralizing antibodies. A few studies reported that patients with ADAs to guselkumab and risankizumab had a higher incidence of injection site reactions (ISRs). There do not appear to be other adverse events associated with ADAs with IL‐23 inhibitors. Testing for presence of ADAs alone in this patient group does not appear to be predictive of treatment response. Clinically, it may be more productive to test for neutralizing antibodies or ADA titre values, although further investigation is required to show a definitive correlation.