The study aims to determine the effectiveness of the use of the Philippine variety "malunggay" seeds as a water purifying agent and also to determine the length of time the "malunggay"-treated water remains potable after treatment. This purification involves the removal of colloidal particles imparting turbidity and the subsequent removal of microorganisms. Twelve types of water samples were artificially prepared in the laboratory with turbidities simulating conditions of the water source in the field, namely: 1) lahar-type water (turbidity 195 NTU), 2) urban-type water (turbidity = 50-100 NTU), and 3) rural-type water (turbidity = 30-51 NTU). In order to determine the seed's effect on different concentrations of bacteria, a mixture of pathogens with bacterial concentrations of 100, 1000, 100000 and 1000000 CFU/ml were seeded to individual water samples each containing one of three levels of turbidity. The seven organisms used in the seeding of the water samples were Escherichia coli, Salmonella typhimurium, Shigella flexneri, Vibrio cholerae non-01, Aeromonas hydrophila, Plesiomonas shigelloides and Streptococcus faecalis.Two groups of water samples (four experimental and four control samples) of each water type were used in the experiments. Before treating the experimental water samples with "malunggay" seed, baseline turbidity and bacterial and coliform counts were determined for both groups. The powdered seed was then applied into the experimental group with appropriate stirring initially at 130 revolutions/minute for 5 minutes. No seed was applied to the control group. Subsequent tests for turbidity and bacterial counts were performed at 2, 4, 8, and 24 hours after seed treatment for the experimental group. Turbidity and bacterial counts were also repeated for the control group simultaneously timed with the experimental group's 2 hour post seed application determination. Philippine variety M. oleifera seeds were found to be effective purifying agents for artificially prepared contaminated and turbid water samples. It primarily causes a reduction in turbidity by coagulating particles in water causing a secondary reduction in bacteria. However, with the 200 mg/L concentration used, its effectiveness varied with initial levels of turbidity and bacterial counts - greater effectiveness was observed with highly turbid water samples with lesser bacterial counts. Though significant reduction in turbidity occurred 2-8 hours after seed treatment, turbidity levels attained fell to acceptable levels only 24 hours after seed treatment. Reductions in bacterial counts varied according to species with counts of E. coli, V. cholerae non-01, and S. faecalis attaining reductions of 36-73% in most instances within 2 hours. On the other hand, counts of Salmonella, Shigella, and Aeromonas were not reduced to such an extent. Bacterial regrowth was noted 4 to 24 hours after treatment which imply that seed treatment should be performed on drinking water more than once daily. Because of these favorable findings, the seeds should therefore be tested on natural waters using appropriate doses and methods to determine its suitability as a purifying agent in the field.