ABSTRACT Objective: To describe a case series of severe acute toxic exposures (SATE) in individuals <20 years old followed-up by a regional Poison Control Center (PCC). Methods: Descriptive cross-sectional study. All patients who were <20yo and classified as score 3 (severe) and 4 (fatal) following Poisoning Severity Score were included for analysis. According to the outcome, patients were classified as PSS 3 when they developed intense clinical manifestations with risk of death or important sequelae; and as PSS 4 when death had resulted from direct cause or complication of the initial exposure. The data of patients were obtained from the Brazilian electronic database system (DATATOX). Results: During the biennium 2014-2015, Campinas PCC followed up 5,095 patients <20yo, with 30 being classified as SATE (PSS=3, n=24; PSS=4, n=6). The exposures circumstances were unintentional (15); intentional (14; suicide attempt = 11; street drugs consumption = 3); and not explained (1). The exposures were significantly more frequent in adolescents >14yo (n=17; p<0.01). The involved agents were venomous animals (8; scorpions=5); medicines (8; miscellaneous=6); chemicals (6); illegal rodenticides containing acetylcholinesterase inhibitors (chumbinho, 4); drugs of abuse (3); button battery (1). Three patients evolved with sequels (esophageal stricture post-corrosive ingestion). The median length of hospital stay was 6 days (IQR: 5-12 days); 26 patients were treated in intensive care units, and 22 of them needed mechanical ventilation; 12, inotropic/vasopressors; and 3, renal replacement therapy. Conclusions: Scorpion stings and poisonings caused by medicines and chemicals were the main causes of SATE. The SATE were significantly more frequent in adolescents, due to deliberate self-poisoning.