question: AIM: We investigated prolonged symptoms in children after COVID‐19, including the clinical characteristics and risk factors. METHODS: This multicentre retrospective study focused on 451 children under 18 years old who were diagnosed with symptomatic COVID‐19 between 14 March and 31 December 2020. Persistent symptoms were analysed with a telephone questionnaire by the attending physicians from 1 August to 30 September 2021. A control group of 98 with no history of COVID‐19, who were treated for other reasons, was also included. RESULTS: Most (82.0%) of the cases had mild infections that required outpatient care and 5.1% were admitted to the paediatric intensive care unit (PICU). We found that 18.4% had symptoms that lasted 4–12 weeks. There were also 14.6% who were symptomatic for longer than 12 weeks and the odds risks were higher for children aged 5 years or more (OR 3.0), hospitalised (OR 3.9), admitted to the PICU (OR 4.3) and with relatives who were symptomatic for 12 weeks or more (OR 2.8). The controls had similar percentages of prolonged symptoms, despite having no history of COVID‐19, especially those who were older than 5 years. CONCLUSION: This study confirmed that a worrying percentage of children had prolonged symptoms after COVID‐19.