The occurrence of increasing HIV-1 reverse transcriptase viral resistance and risk of toxicity drive open the opportunities in using ethno-medicinal plants for the management of HIV/AIDS. The study aimed to determine the inhibitory activity of Mentha cordifolia Opiz buffered crude extract against recombinant HIV-1 reverse transcriptase and determine its mechanism through enzymatic inhibition kinetic study. The study followed an experimental design that made use of the colorimetric immunoassay, Roche 13.0, to directly measure the inhibition through absorbance measured at 405 nm with a reference wavelength set at 492 nm bichromatic filter. The enzyme velocities were calculated to elucidate enzyme kinetics. M. cordifolia Opiz buffered extract inhibited up to 67.67±5.64% (IC50, 368.39ug/mL) viral activity, which was significantly different with Nevirapine, positive control, at 93.13±0.18% (IC50, 0.241ug/ mL), p < .05. Despite the significant difference in its activity when compared with Nevirapine, it may exhibit the same activity on equipotent concentrations, p .508. The M. cordifolia Opiz follows a non-competitive or mixed inhibition with respect to the dUTTP substrate. Its kinetic pattern is consistent with those of other non-nucleoside reverse transcriptase inhibitors. The researcher recommended for further purification of the extract and analysis. M. cordifolia Opiz plant buffered crude extract is a potential novel HIV-1 Reverse transcriptase inhibitor.