Evaluation of the genotoxic effect of malaria in a cohort of patients in Medellín and QuibdóIntroduction: During malaria infection, both parasite and host are under the effects of oxidative stress due to the increased production of reactive oxygen species, which can induce DNA damage by its genotoxic effects.Objective: To evaluate genotoxic effects in human lymphocytes in a cohort of patients with malaria from Medellin and Quibdó.Methods: We performed an observational cross sectional study in 100 individuals with malaria and 100 healthy controls.Patients infected with Plasmodium consulting the Institute Colombiano of Medicina Tropical of Medellin and the Hospital Ismael Roldán Valencia of Quibdó were included.Genotoxic effects (genetic damage) was analysed by electrophoresis using alkaline single cell gel (Commet assay).Results: The average of tail length of malaria samples (26.9 ± 9.8) was significantly higher than of controls (14.8 ± 3.2) (p < 0.01).Conclusion: In our study population, malaria infection was associated with increased genotoxicity, while other variables such as smoking, antimalarial treatment, and occupation were not.