In this study, Phyllanthus acidus juice extract was tested for possible antibacterial activity against E. coli at various concentrations using the Kirby-Bauer Disk Diffusion Assay. The four different extract concentrations used in the experiment were 25%, 50%, 75%, and 100%. Gentamicin was used as the positive control and distilled water as the negative control. There were three trials in the experiment, and each trials mean absorbance was 6 mm. The positive controls mean absorbance was 19 mm. By comparing the experimental group to the positive control, the statistical analysis revealed a P-value of 0.0001, which denotes a highly significant effect. The efficiency of Phyllanthus acidus extract at various concentrations against E. coli however, did not differ noticeably. as the P-value of 0.00 was higher than the confidence interval of 0.05. The conclusion drawn from this is that there are no discernible differences in the antibacterial properties of Phyllanthus acidus juice extract against varying levels of E. coli.