A high-performance liquid chromatography analysis method with an evaporative light-scattering detector has been developed for the separation and quantitative analysis of free fatty acids in biological matrices. Core-shell reversed-phase high-performance liquid chromatography separation of 10 free fatty acids is achieved within 10.5 min using a methanol/water (0.05% trifluoroacetic acid) eluent gradient. After optimization, the drift tube and nebulization temperature of the evaporative light-scattering detector was set at 35°C, nitrogen flow-rate at 1.1 standard liter per minute and column temperature at 25°C. All calibration curves showed good regression (r² > 0.9975). A validation procedure following the International Conference on Harmonisation guidelines was implemented to certify the method. Relative standard deviations did not exceed 1.5% and 4.25% for repeatability and reproducibility respectively.