Background Asthma is one of the most prevalent non-communicable diseases worldwide. The aim of this study was to characterize the distribution of Brazilian hospital admissions due to asthma among children and teenagers between 1998 and 2019, as well as to analyze hospital admission incidence and mortality rate during the period according to the geographic region, age group and gender. Methods This is a descriptive time trend study using secondary data regarding hospital admissions and lethality registered in the Brazilian System of Hospital Information of the Brazilian Public Health System (SIH/SUS) due to asthma (ICD-10) in subjects aged from 0 to 19 years old between 1998 and 2019. The following variables were collected: number and place of hospital admissions classified by the ICD-10, absolute values and frequency by age group, gender and lethality. Statistical analysis was performed by GraphPad Prism version 5.0 software. Results The total number of hospital admissions due to asthma was 3,138,064. It was observed that children aged between 1 to 4 years, living in the Northeast region and males showed the highest number of hospitalizations. A 74.37% reduction over a 21-year period was found. The lethality rate found in the study was 0.06, with the highest rates being from the Northeast region, males and Conclusion Hospital admissions were more prevalent in young children, male gender and in the Northeast region. A decrease of hospital admissions and lethality rate was observed in all groups over time. This profile is important for implementing government strategies to lower hospital admissions and decrease costs.