Plants have been used in folk medicine by Mayan ancient people from the Yucatan Peninsula, Mexico, to treat some diseases considered as cancer diseases such as chronic wounds or tumors.We collected a selection of nine plants in order to investigate their cytotoxic activity against cancer cell lines.Methanolic extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on four cancer cell lines; nasopharynx carcinoma (KB), laryngeal carcinoma (Hep-2), cervix adenocarcinoma (HeLa), and cervix squamous carcinoma cells (SiHa) and one normal cell line; canine kidney (MDCK).All species exhibited some degree of cytotoxic activity. The root bark extract of Hamelia patens exhibited the highest cytotoxic activity on HeLa cells with a CC50 of 13 microg/mL and selectivity index of 13.3, higher than docetaxel. Gossypium schottii and Dioon spinulosum showed similar good cytotoxic activity and selectivity index on HeLa and Hep-2 cells, respectively.Hamelia patens, Dioon spinulosum and Gossypium schottii demonstrated promising cytotoxic activity and have been selected for future bio-guided fractionation and isolation of active cytotoxic compounds.