Background & Aims: Diabetes mellitus is one of the most common types of chronic disease leading to serious complications such as blindness, end stage renal disease (ESRD), neuropathy and cardiac disorders. Skin tag is a common benign skin tumor that its association with impaired carbohydrate metabolism has been reported in some studies. The aim of this study was to compare the frequency of diabetes and other carbohydrate metabolism disorders in patients with and without skin tag. Methods: In a case- control study on 200 individuals over 30 years old referring to Dermatology Clinic of Afzalipour Hospital, 100 individuals with at least 3 skin tags as case group and 100 individuals without skin tag as control group underwent FBS and standard GTT tests. Results: There was no significant difference between case and control groups in the frequency of diabetes (19% vs. 10%), IGTT (11%vs.13%) and IFG (19% vs. 15%).Mean FBS and GTT were significantly higher in the case group compared to the control group. There was a positive correlation between the total number of skin tags and mean FBS (r= 0.33, P= 0.001) and GTT (r= 0.37, P= 0.000). The frequency of diabetes in patients with at least 20 skin tags was 45.8%. Positive predictive value, negative predictive value, sensitivity and specificity of skin tag for the diagnosis of diabetes were 19%, 90%, 52% and 65% respectively. Conclusion: This study revealed that patients with skin tags are at a higher risk of carbohydrate metabolism disorders. Therefore, screening of patients with skin tag for carbohydrate metabolism disorders is recommended.