ObjectiveTo systematically compare the risk of adverse events (AEs) for 13 targeted immunomodulators (TIMs) indicated for ankylosing spondylitis (AS), inflammatory bowel diseases, juvenile idiopathic arthritis, plaque psoriasis, psoriatic arthritis (PsA), or rheumatoid arthritis (RA).MethodsWe searched electronic databases through July 2015 to retrieve randomized controlled trials (RCTs) and observational studies comparing AEs between 2 or more TIMs head‐to‐head. We reported on the following outcomes: number of AEs, discontinuation due to AEs, serious AEs, mortality, serious infections, tuberculosis, herpes zoster, and malignancies. We qualitatively synthesized the literature and conducted random‐effects meta‐analyses if 3 or more studies provided data for an outcome.ResultsTen head‐to‐head RCTs and 51 observational studies were included in this systematic review. A majority of the studies (70%) were conducted in RA patients. Risk of treatment discontinuation due to AEs was higher with infliximab than with adalimumab or etanercept in RA, PsA, and AS. A higher risk for serious infections was noted with infliximab than with abatacept, adalimumab, or etanercept in RA. Risk for treatment discontinuation due to AEs, serious infections, and tuberculosis was lower with etanercept than with adalimumab in RA. Limited evidence suggested no comparative differences in risk for mortality, malignancies, and herpes zoster for adalimumab, etanercept, and infliximab in RA.ConclusionImportant differences were noted in the safety profile of TIMs in RA, generally favoring abatacept, adalimumab, and etanercept over infliximab. Head‐to‐head comparative evidence for other TIMs and non‐RA populations was insufficient to draw conclusions for most of the safety outcomes.