Nickel is a well - known contact allergen which is verified by 5 % nickel sulfate in petrola¬tum. However this standard test produces false negative reactions and gives numerous problems. For this purpose, we tried to confirm suspicious nickel allergy using DMSO (Dimethyl Sulfoxide) as a test vehicle with different concentration for nickel. In this study the evaluation of nickel sulfate patch test results with DMSO, showed that; patient anam¬nesis, patch test vehicle, patch test material and occlusion time are needed to establish the right, less irri¬tant patch test method for nickel allergy.