During the COVID-19 pandemic, the proportion of SARS-CoV2 cases and related deaths is lower in children and adolescents than in adults. Aim: to describe the transmission and severity of SARS-Cov-2 infection among children and adolescents during the different waves of the pandemic in Tunisia. Methods: A national descriptive study was conducted from March 2020 to August 2022. Data was extracted from the National Database of SARS-Cov2 Cases including those under 18 years of age. The transmission and severity indicators calculated were: cumulative incidence, hospitalization rate, mortality rate and case fatality. Results: A total of 104517 COVID-19 cases (9.1% of total new cases), 137 deaths (0.46% of total deaths) and 2390 hospitalizations (8.5% of total hospitalizations) were reported among children and adolescents. The cumulative incidence per 100 000 children was 3101.88. The mean age of cases was 11.14 ± 4.85 [0– 17] years with a sex ratio(M/F) of 0.97. The mortality rate per 100 000 children was 4.07. The median age of deaths was 2 months with an interquartile range [0-13 years]. Sex ratio (M/F) was 1.45. The overall case lethality was 0.13%. The overall hospitalization rate was 2.3%. Median age of hospitalizations was 1 month with an interquartile range [4.9-17years]. Sex ratio (M/F) was 1.36. The cumulative incidence was higher among those aged between 15 and 18 years. The crude death rate, lethality and hospitalization rate were higher in the group age [0-5 years [. The epidemic curve showed that the highest incidence was observed during the omicron outbreak (Incidence =1621.9/100000 children). However, the highest mortality rate was recorded during the Delta outbreak (2.1/100000 children). Conclusions: Sars-Cov2 infection, associated deaths, and hospitalizations in the pediatric population are not negligible. The highest severity indicators were observed in the youngest age group, thus the need to consider vaccination of children in Tunisia.