We report on children with cancer in Hungary suffering from COVID-19, surveying a 13-months-long period of time. We performed a retrospective clinical trial studying the medical documentation of children treated in seven centers of the Hungarian Pediatric Oncology-Hematology Group. About 10% of children admitted to tertiary hemato-oncological centers for anti-neoplastic treatment or diagnosis for de novo malignancies were positive for SARS-CoV-2 infection. Nearly two-thirds of the infected patients were asymptomatic or had only mild symptoms but showed seropositivity by 1-4.5 months after positive PCR. One third of the SARS-CoV-2-positive children were hospitalized due to symptomatic COVID-19. Five children required antiviral treatment with remdesivir. One child was referred to the intensive care unit, requiring intubation and mechanical ventilation. Delay in the scheduled anti-cancer treatment did not exceed 2 weeks in the majority (89%) of cases. There was only one patient requiring treatment deferral longer than a month. There was no COVID-19-related death in patients under 18 years of age, and nor was multisystem inflammatory syndrome diagnosed. In conclusion, SARS-CoV-2 infection did not represent an untoward risk factor among children with cancer in Hungary.