<p>The efficient and accurate quantification of viable bacteria in oyster sauce, which is a well-known premium&#xa0;condiment, remains a great challenge. Herein, a culture-based method for quantifying viable bacteria is developed by employing an electrical microbial growth analyzer (EMGA), using <i>Staphylococcus aureus</i> and <i>Vibrio parahaemolyticus</i> as microorganism models. Oyster sauce samples were diluted with liquid broth, and subsequently loaded into test tubes. The test tubes were positioned into the EMGA to determine bacterial growth curves and the key growth kinetic parameter—the time required to reach the maximum growth rate (<i>T</i>_mgr). Based on the linear relationship between the logarithmic value of bacteria and <i>T</i>_mgr, the concentrations of viable bacteria in target samples were subsequently calculated. For <i>Staphylococcus aureus</i>, the linear range was 10¹–10⁷&#xa0;CFU/mL (<i>r</i> = 0.9876) with recovery rates of 97.84–113.12% and coefficients of variation of 7.53–30.82%. For <i>Vibrio parahaemolyticus</i>, the linear range was 10¹–10⁶&#xa0;CFU/mL (<i>r</i> = 0.9975) with recovery rates of 87.53–104.90% and coefficients of variation of 8.17–23.52%. When the concentration of <i>Vibrio parahaemolyticus</i> in oyster sauce samples was 10⁴&#xa0;CFU/mL, the overall assay turnaround time did not exceed 380&#xa0;min. Merely four manual operations were entailed. The cost was approximately $0.5 per sample. This novel method outperformed the classical plate counting method in terms of simplicity, efficiency, precision, accuracy, and cost-effectiveness, and thus held great promise as an alternative for assessing bacterial contamination in oyster sauce products.</p>