Abstract: Association between dietary habits and development or exacerbation of acne vulgaris has been an interesting topic for many years. The goal of the present study was to investigate possible association between pepper (red and black pepper, separately) consumption and changes in acne lesions. A total of 45 volunteers with mild-to-moderate acne vulgaris were recruited from a private clinic and enrolled in this case-control, clinical trial. Patients were randomized in three equal age and sex-matched groups, receiving 8 mg of either red or black pepper powder mixed with their food at lunch for 30 consecutive days (cases); or no additive to food was added (controls). In red pepper group there were 11 males (73.3%) and 4 females (26.7%) with a mean age of 17.8±5.1 years (range: 12-27). In black pepper group there were 6 males (40%) and 9 females (60%) with a mean age of 17.9±6.3 years (range: 12-29). In control group there were 10 males (66.7%) and 5 females (33.3%) with a mean age of 16.6±5.2 years (range: 12-27). The three groups were comparable for sex (p = 0.14) and age (p = 0.78). Changes in the mean number of noninflamed, inflamed or total lesions within the study period did not differ significantly between three study groups (p = 0.22, 0.54 and 0.46, respectively). In patients receiving red pepper, mild amelioration of acne lesions was documented. According to the findings of this study, neither black pepper, nor red pepper is associated with exacerbation of acne lesions. Red pepper even may have mild ameliorating effect on acne lesions.