Initial reports on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in children suggested that very young age and comorbidities may increase risk of severe evolution, but these findings remained to be confirmed. We aimed to analyze the clinical spectrum of hospitalized pediatric SARS-CoV-2 infection and predictors of severe disease evolution. We conducted a French national prospective surveillance of children hospitalized with SARS-CoV-2 infection. We included all children with confirmed SARS-CoV-2 infection in 60 hospitals during February 15 to June 1, 2020. The main outcome was the proportion of children with severe disease, defined by hemodynamic or ventilatory (invasive or not) support requirement. We included 397 hospitalized children with SARS-CoV-2 infection. We identified several clinical patterns, ranging from paucisymptomatic children, admitted for surveillance, to lower respiratory tract infection or multisystem inflammatory syndrome in children. Children <90 days old accounted for 37% of cases (145 of 397), but only 4 (3%) had severe disease. Excluding children with multisystem inflammatory syndrome in children ( = 29) and hospitalized for a diagnosis not related to SARS-CoV-2 ( = 62), 23 of 306 (11%) children had severe disease, including 6 deaths. Factors independently associated with severity were age ≥10 years (odds ratio OR = 3.4, 95% confidence interval: 1.1-10.3), hypoxemia (OR = 8.9 2.6-29.7), C-reactive protein level ≥80 mg/L (OR = 6.6 1.4-27.5). In contrast with preliminary reports, young age was not an independent factor associated with severe SARS-CoV-2 infection, and children <90 days old were at the lowest risk of severe disease evolution. This may help physicians to better identify risk of severe disease progression in children.