Objectives: Pediatric cardiac catheterization is a diagnostic and management tool in congenital heart disease. It has advantages over surgical procedures; however, it is not free of serious adverse events. Despite its extensive use, these outcomes or the associated risk factors have not been properly evaluated, particularly in South America. The objective of the study was to determine the risk factors associated with adverse events related to pediatric cardiac catheterization in a hospital in southwestern Colombia. Methods and results: The clinical histories of pediatric patients who underwent diagnostic and therapeutic cardiac catheterization from January 1, 2018 to June 1, 2023 were reviewed. Sociodemographic data, physiological variables from the previous state, during, and those related to the procedure were tabulated. A statistical analysis was performed to determine the factors that were associated with adverse events. A total of 986 clinical records were evaluated, finding in 2.07% serious adverse events, and unadjusted association with the variables route of admission, risk category of the diagnosis and diagnoses that motivated the procedure (patent ductus arteriosus and valvular atresia), hemodynamic stability, ASA category, airway management before and during the procedure, closure of intra- or extracardiac defects. Statistical significance was found in the multivariate analysis with the variables admission route and hemodynamic stability, with the risk 2,32 times 95% CI [1,14– 4,96%] and 2,96 times 95% CI [1,81 – 18,65%] respectively. Conclusions: A lower incidence of serious adverse events was found than that reported worldwide. The route of admission, as well as the hemodynamic stability prior to the procedure, are factors that showed an association with serious adverse events, which indirectly inform the patient's physiological state, so it is important to achieve as much clinical stability as possible before performing the procedure cardiac catheterization. No statistically significant data was found regarding variables related to the procedure.