Many reports state that different structures of M. grandiflora contain bioactive components. Nonetheless, phytochemical studies reported that the extracted essential oils are chemically different and remarkably variable in their qualitative and quantitative compositions. Further studies Mexican M. grandiflora needs to be done. Thus, the research aimed to characterize a) the chemical composition, b) the antioxidant activity and c) cytotoxicity effect of two M. grandiflora flower extracts. The chemical composition was evaluated by preliminary phytochemical test followed by thin layer chromatography, UV-Vis and FTIR spectrophotometer analysis. The antioxidant activity of the flower extracts was measured by the free radical-scavenging activity (ABTS) and the stable radical of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) method and the cytotoxicity by an Artemia salina bioassay. Water and ethyl flower extracts showed the presence of organic chromophores such as flavonoids. Both extracts (ethyl and water) demonstrated antioxidant activity by both ABTS (459.6±8.5 µmol TE g-1 and 274.2±5.7 µmol TE g-1 respectively) and DPPH (3210.4 ± 2.5 µmol TE g-1  and 219.7 ± 0.9 µmol TE g-1  respectively) methologies; and non-cytotoxic activity (LC50 , µg mL-1) (1,285 ± 14  and 1,116 ± 15 respectively). The water and ethyl extracts of M. grandiflora flowers found in southeast Mexico are a promissory source of chemical compounds with attributed biological activity according to the presented results.