An effective, simple and rapid analytical method using HPLC was developed for the analysis of monosodium glutamate (MSG) in various food samples obtained from local market in Turkey. The determination of MSG was performed by its derivatisation with o‐phthaldialdehyde (OPA). A high‐performance liquid chromatography‐ultraviolet/diode array detection method was performed by using C18 (150 mm × 4.6 mm, 2.7 μm) column with the mobile phase consisting of 10 mm phosphate buffer solution (pH = 5.90) and methanol (75:25, v/v). The applied method was optimised and the validated. The method was linear from 1 to 50 μg mL−1 of MSG. The correlation coefficient value of the developed method was obtained as R2 = 0.9999. The limit of detection and limit of quantification limits were 0.015 and 0.050 μg mL−1, respectively. MSG contents of the food samples range from 0.09 g kg−1 to 120.80 g kg−1. The validated method was successfully applied for the analysis of MSG in several food samples.