Objective: To screen the cytotoxic activity of Melastoma malabathricum (M. malabathricum) against human breast cancer cell line (MCF-7) in vitro. Methods: A three steps extraction protocol using n-hexane, chloroform and methanol as the solvents systems was carried out on leaves, stems and flowers of M. malabathricum. Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations (100 μg/mL, 50 μg/mL, 25 μg/mL, 12.5 μg/mL and 6.25 μg/mL). The evaluation of cell growth was determined using methylene blue assay. Results: Methanol extract from the leaves showed significant anticancer activity against MCF-7 cell lines with the IC50 value of 7.14 μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line with the IC50 value of 33.63 μg/mL and 45.76 μg/mL respectively after 72 h of treatment. Conclusions: The extracts from leaves and flowers of M. malabathricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC50 at 7.14 μg/mL while the extracts from stems showed less growth inhibition activity.