Manihot esculenta, also named cassava, is a plant widely used as food but also in traditional medicine to treat many diseases such as anemia. However, consumption of M. esculenta is limited by its content in cyanogenic glycosides. Few studies have evaluated the toxicity of M. esculenta leaves. This study aims to evaluate the in vitro cytotoxicity of Artemia salina and the 28 days subchronic toxicity of M. esculenta leaves by oral administration of the extract to male Wistar rats. The A. salina assay showed that the alcoholic extract of M. esculenta presented some toxicity. The results of 28 days subchronic toxicity showed a significant increase in the relative weight of the liver. No changes in hematological parameters were observed apart from a significant increase in platelet number. Biochemical parameters such as SGOT, SGPT, glycemia, and ALP were not significantly changed. The histological sections showed no organ damage.