Chagas disease (ChD) affects approximately 7 million people in Latin America, with benznidazole being the most commonly used treatment. Data from a retrospective cohort study in Argentina, covering January 1980 to July 2019, was reanalysed to identify and characterize benznidazole-related adverse drug reactions (ADRs). The study included 518 patients: 449 children and 69 adults (median age in children: 4 years; adults: 25 years; age ranges: 1 month-17.75 years and 18-59 years, respectively). The median benznidazole doses received were 6.6 mg/kg/day for at least 60 days in children and 5.6 mg/kg/day for a median of 31 days in adults. Overall, 29.34% (152/518) of patients developed benznidazole-related ADRs, with an incidence of 25.83% (116/449) in children and 52.17% (36/69) in adults (odds ratio [OR] = 0.32, 95% confidence interval [CI] = 0.19-0.54, P