SummaryBackgroundInformation regarding the impact of paternal inflammatory bowel disease (IBD) medications on child outcomes is scarce.AimTo examine the risk of childhood infections associated with fathers' use of anti‐inflammatory/immunosuppressive medications taken before conception.MethodsThis is a nationwide cohort study based on Danish health registries, comprising all live‐born singleton children born between January 1997 and February 2019 who were fathered by men with IBD. Exposed cohorts included children fathered by men treated with 5‐aminosalicylates (5‐ASAs), thiopurines, corticosteroids or anti‐tumour necrosis factor‐α (anti‐TNF‐α) agents within 3 months before conception. The unexposed cohort included children not exposed to paternal IBD medications. Outcomes were the first infection, diagnosed in the hospital setting in the first year of life, and from the age of 1 to 3 years.ResultsIn all, 2178 children were fathered by men exposed to 5‐ASAs, 843 to thiopurines, 417 to systemic corticosteroids and 436 to anti‐TNF‐α agents; 6799 children were unexposed. The adjusted hazard ratio (aHR) for infections within the first year of life for 5‐ASAs was 0.78 (95% CI, 0.66–0.91), thiopurines 0.89 (95% CI, 0.73–1.09), systemic corticosteroids 0.95 (95% CI, 0.70–1.29), and anti‐TNF‐α agents 1.17 (95% CI, 0.94–1.46). The aHR for infections from 1 to 3 years for 5‐ASAs was 0.97 (95% CI, 0.83–1.13), thiopurines 0.87 (95% CI, 0.71–1.07), systemic corticosteroids 1.25 (95% CI, 0.94–1.65), and anti‐TNF‐α agents 0.79 (95% CI, 0.60–1.03).ConclusionFathers' use of anti‐inflammatory/immunosuppressive medications before conception was not significantly associated with childhood infections. These results fill an important research gap regarding paternal medication safety.