Today, using counterfeits is remarkably common in clothing industry. On this basis, present paper is conducted in clothing industry at Tehran due to the impact of counterfeit on brand equity of original products’. It is a descriptive research. To achieve research aims, a sample consisting of 384 consumers in Tehran who bought counterfeits deliberately were selected. To analyze data and to test hypotheses, Structural Equation Modeling (SEM) and Confirmatory Factor Analysis (CFA) as well as LISREL and SPSS software packages were used. By studying existing literature, six variable including personal gratification, value averseness, price-quality perception, ethical issues, subjective norm and perceived risk were considered as affecting factors on customers’ attitude on counterfeits. To measure brand equity, four aspects of Aaker’s aspects (perceived quality, brand consciousness, brand association and brand loyalty) were used. Research findings indicate that personal gratification, value averseness, price–quality perception and perceived risk have a significant impact on attitudes towards counterfeits. Likewise, the impact of counterfeits on Brand Equity of Original products is also significant.