Background: A new stability indicating RP-HPLC based assay method was developed to quantify ivermectin and praziquantel simultaneously and applied effectively to tablets. Methods: The simultaneous assay of ivermectin and praziquantel by RP-HPLC was done using an YMC C18 (250 mm × 4.6 mm, 5 µm) column with a mobile phase mixture of 0.1M disodium hydrogen phosphate (pH 4.5) and acetonitrile (55:45, v/v) using a isocratic flow rate of 1.0 ml/min and measured at 242 nm using photodiode array detector. All parameters were validated following the ICH guiding principles. The method was applied to quantify ivermectin and praziquantel simultaneously in tablets. Results: The retention values of ivermectin and praziquantel were 3.465 min and 4.468 min, respectively. The method’s linearity was found to be 1-3 µg/ml (ivermectin) and 25-75 µg/ml (praziquantel). The limit of detection was 0.010 µg/ml (ivermectin) and 0.046 µg/ml (praziquantel); limit of quantification was 0.033 µg/ml (ivermectin) and 0.155 µg/ml (praziquantel). The percent relative standard deviation of ivermectin and praziquantel was ˂1.0%. The percent assay was 99.51% and 99.20% for ivermectin and praziquantel, respectively. In tablets, the percent recovery of ivermectin and praziquantel was 99.60% and 99.38% with a percent relative standard deviation value of 0.353% and 0.106%, respectively. Stability indicating capability of the method was demonstrated through the stress degradation studies. Conclusion: The developed method was proved to be selective, precise and accurate for the quality control of ivermectin and praziquantel in tablets.