Introduction: Various factors are involved in the pathogenesis of acne vulgaris. Recently, G6PD deficiency has been proposed in the pathogenesis of acne. G6PD has an important role in the oxidant/antioxidant balance. According to this theory, antioxidants are used in the treatment of acne recently. The aim of this study was to evaluate G6PD deficiency in patient with acne vulgaris. Methods: The activity of G6PD enzyme was measured in the venous blood of 82 patients with acne vulgaris of different severity. The fluorescent lamp method was used in order to determine the activity of G6PD enzyme. Results: The mean age of the patients was 25± 3. From 82 patients, the level of the G6PD enzyme was normal in 77 (93.9%) patients. Also, 4 (4.9%) patients had relative G6PD deficiency and 1 (1.2%) patient had severe G6PD deficiency. As the incidence of G6PD deficiency is 5.7% in the normal population, there was no statistically significant difference in G6PD deficiency between patients and the normal population. No significant relationship was found between acne severity and G6PD deficiency. Conclusion: In order to detect the association between acne and G6PD deficiency, other case-control studies with lager sample sizes are recommended.