AbstractAimChildren have largely been unaffected by severe COVID‐19 compared to adults, but data suggest that they may have experienced new conditions after developing the disease. We compared outcomes in children who had experienced COVID‐19 and healthy controls.MethodsA retrospective nested cohort study assessed the incidence rate of new‐onset conditions after COVID‐19 in children aged 0–14 years. Data were retrieved from an Italian paediatric primary care database linked to Veneto Region registries. Exposed children with a positive nasopharyngeal swab were matched 1:1 with unexposed children who had tested negative. Conditional Cox regression was fitted to estimate the adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for the exposure and outcome associations after adjusting for covariates.ResultsWe compared 1656 exposed and 1656 unexposed children from 1 February 2020 to 30 November 2021. The overall excess risk for new‐onset conditions after COVID‐19 was 78% higher in the exposed than unexposed children. We found significantly higher risks for some new conditions in exposed children, including mental health issues (aHR 1.8, 95% CI 1.1–3.0) and neurological problems (aHR 2.4, 95% CI 1.4–4.1).ConclusionExposed children had a 78% higher risk of developing new conditions of interest after COVID‐19 than unexposed children.