Background: Curcumin and quercetin are the two important flavonoids that are being used as food ingredients across the globe. They also possess many pharmacological activities such as anti-inflammatory, anticancer and antidiabetic activity. The combination of both these phytoconstituents is available in the market. However, there is lack of any suitable analytical method reported for their simultaneous estimation in food as well as pharmaceutical products. Hence, there is a need to develop a simultaneous method for them. Objectives: The study aims to develop and validate a simple high-performance liquid chromatography (HPLC) method for the simultaneous determination of curcumin and quercetin. Method: Gradient elution was carried out in ACN and GAA (2% v/v) for 15 min wherein the ratio of ACN and GAA was varied from 40-60 v/v ACN: 60-40 GAA v/v from 0-5 min followed by 60-80 v/v ACN: 40-20 v/v GAA between 7-10 min followed by 80 % ACN: 20 % GAA between 10-15 min. The flow rate was kept 1 mL/min and detection wavelength at 395 nm. The method has been validated according to International Conference of Harmonization (ICH) Q2 (R1) guidelines with respect to specificity, system suitability, accuracy, precision, and robustness. The developed method was further used for the determination of curcumin and quercetin in different herbal extracts, marketed formulations containing these drugs and developed self-nano emulsifying drug delivery system (SNEDDS). Results: The method was linear in the concentration range of 50-250 ng mL1 for curcumin and 800-1600 ng mL À1 for quercetin, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 11.76 and 35.6 ng mL À1 for curcumin, respectively, while LOD and LOQ for quercetin were 32.94 and 99.76 ng/mL À1 , respectively. The percentage recovery that was found to be in the range of 95-105% with relative standard deviation less than 2% indicating the accuracy and precision of method for both the drugs. Further, the validated method was found specific to detect presence of both the drugs in extracts, marketed formulations and developed SNEDDS. Conclusions: The developed method showed excellent specificity, linearity, accuracy and precision. Thus, it can be further explored to detect curcumin and quercetin in biological samples as well as other marketed formulations.