Introduction: Pediatric diseases and their main causes of hospitalization are directly related to simple outpatient measures, sensitive to basic care. However, there were changes in the epidemiological and clinical scenario of hospitalizations for these diseases, with the advent of the covid-19 pandemic. Objective: To study the causes of hospital admissions for children and adolescents aged 0 to 18 years old and their evolution from 2020 to 2022, in the city of Campina Grande/PB. Methodology: This is a descriptive, cross-sectional and retrospective study, carried out with data obtained from the Hospital Information System (SIH), searching for the main causes of hospital admissions for children and adolescents admitted to pediatric reference services in Campina Grande. The variables used were biological characteristics (sex, age) and clinical characteristics (number of hospitalizations; length of stay; hospital discharge conditions; deaths). Results: The main cause of hospitalization in the group of pediatric diseases in the three years studied was pneumonia due to non-specific microorganisms (PNM), corresponding to 9.9% of hospitalization cases in 2020; 12.5% in 2021 and 15.8% in 2022. Another important highlight was lymphoid leukemia (ALL), which accounted for 2.6% of cases in 2020; 4.2% in 2021 and 4.3% in 2022. In the group of neonatal and infant diseases, the main causes of hospitalizations were disorders related to short-term pregnancy and low birth weight, represented by 10.3% of cases in 2020, 7.4% in 2021 and 6.4% in 2022. Discussion: The consequences of the pandemic were the progressive increase in the incidence of respiratory diseases, with the return of classes and exposure to viruses and bacteria, after isolation prolonged social. In addition to the progressive increase in the incidence of premature births, directly related to teenage pregnancy, considered a public health problem. And the incidence of ALL, which was underdiagnosed in 2020, as most resources were directed to the pandemic. Conclusion: the pandemic impacted pediatric epidemiology, increasing the number and profile of hospitalizations, mainly due to respiratory diseases and oncological diseases.