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Aims: Currently, we face the serious problem of multiple drug-resistant pathogens. The development of new antimicrobial agents is very costly and time-consuming. Therefore, the use of medicinal plants as a source of alternative antibiotics or for enhancing antibiotic effectiveness is important. Methods: The antibacterial effects of aqueous extracts of the seed coat of <i>Pongamia pinnata</i> (Linn.) Pierre in combination with several antibiotics against methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) were tested by broth dilution, checkerboard, and time-kill methods. Results: For the combinations of <i>P. pinnata</i> with ampicillin, meropenem, cefazolin, cefotaxime, cefpirome, and cefuroxime, 70% to 100% were synergistic, with a fractional inhibitory concentration (FIC) index of &lt; 0.5. For the time-kill method with 0.5&#215; minimum inhibitory concentration (MIC) of <i>P. pinnata</i> in combination with 8, 4, 2, and 1 &#181;g mL^&#8722;1 of the various antibiotics, almost all of the combinations showed synergistic effects, even with the lowest concentrations of <i>P. pinnata</i>, except for aztreonam. No antagonistic effect was observed for these combinations. Conclusions: Based on these findings, aqueous seed coat extracts of <i>P. pinnata</i> have good potential for the design of new antimicrobial agents.