Response surface methodology is employed to investigate the optimum evaporative light scattering detector (ELSD) operating conditions for high performance liquid chromatography (HPLC) analysis of frondoside A, which is a bioactive compound valuable for its anti-cancer activity. The results suggest that ELSD response is mostly affected by nebulizing gas flow rate and evaporator temperature. The optimum response of frondoside A is achieved by adjusting ELSD evaporator and nebulizer temperature at 80 °C and 35 °C, respectively, with nebulizing gas flow rate of 0.9 SLM. The analysis of variance (ANOVA) test results demonstrated that the established model can successfully describe the relationship between the signal response and ELSD experimental parameters, and predict the optimum ELSD parameters for frondoside A analysis. Furthermore, analytical method validation performed in optimum conditions shows that the proposed method also exhibits adequate sensitivity and linearity, with acceptable precision and accuracy. The results demonstrate the suitability of HPLC-ELSD technique for the development of routine analysis procedures of frondoside A in natural product samples.