Sansevieria zeylanica is a species of xerophytic perennial herbs with a wide range of distribution found in dry tropical and subtropical parts of the world. It is a wonderful medicinal plant and holds the widespread range of beneficial properties. The aim of the study is to determine the cytotoxic activities of the human breast cancer - MDA-MB-231 cell lines and to evaluate the anti-microbial activities by employing the methanolic leaf extracts of S. zeylanica plants. The main experiment was to determine the susceptibility of a microbial organisms against the methanolic leaf extracts of S. zeylanica. The percentage growth inhibition was calculated and concentration of sample to inhibit cell growth by 50 % (IC50) values was generated for the percentage viability. The leaf extracts produced from S. zeylanica plants showed a cytotoxic effect against the human breast cancer - MDA-MB-231 cell lines. The IC50 value of 1167.78 µg/ ml was obtained for the MDA-MB-231 cell lines after the exposure of 24 h treatment. The increase in cell death of MDA-MB-231 cell lines with an increase in the concentration indicates that the methanolic leaf extract of S. zeylanica plants was found active. For the first time, we made an attempt to examine the biological properties of methanolic leaf extracts from S. zeylanica plants with reference to their wide applications. The results obtained support for the therapeutic applications and this acts as an anti-microbial agent. These studies showed the results from the phytochemical screening, anti-microbial and cytotoxic activities of S. zeylanica indicating that this plant as a “natural herbal source”. This can be used for its pharmaceutical and pharmacological applications in a large-scale industry. پرونده مقاله