Microbial resistant is getting dangerous day by day. To find a new antimicrobial source is very essential. The current research study was designed to assess the antimicrobial activity of methanol extract of Phyllanthus beillei H. by disc diffusion method. By measuring zone of inhibition mild antimicrobial activity of Bacillus subtilis was found and compared with the standard Ciprofloxacin. From the result it can be concluded that Phyllanthus beillei H. plant may be a source of antimicrobial constituents. The plant extract also demonstrated a promising cytotoxic activity against brine shrimps nauplii. The value of LC₅₀ of methanol extract of Phyllanthus beillei H. was 2.4119 mg/mL which compared with the LC₅₀ value of standard (0.0171mg/mL). The overall results indicate a strong cytotoxic activity of this plant.