Statement of Problem: The most important failure factor of root canal treatment is lack of proper seal of root canal, which leads to leakage and penetration of microorganism in to the canals. Different methods have been used to determine the apical seal.Purpose: This study was aimed at comparing the apical leakage using dye penetration and electrochemical methods successively used on the same teeth.Materials and Method: For this experimental study, 31 freshly extracted anterior single root human teeth with straight root canals were selected. The specimens were randomly divided into experimental, positive and negative control groups. Root canals of the experimental and negative group were filled, and positive group were left unfilled. The external surface of each tooth was coated with two layers of the nail polisher, except for the apical 2mm and coronal portion. Leakage of the teeth were measured using electrochemical me thud. Two copper wires were used as electrodes and normal saline solution was used as electrolyte. Then coronal portions of the roots were filled using ZOE cement and coated with two layers of the nail polisher. The teeth were immersed in 2% basic Fuchsine for 48 hours and were washed in tap water. The roots were then split longitudinally and dye penetration was assessed for each tooth. The data were analyzed using t-test and Pierson correlation coefficient test.Results: The obtained results in electrochemical methods varied from 3.1 to 54.7 Micro amper, while in dye penetration method the observed leakage was 2.5 to 6.8 mm. The coefficient correlation between the two methods was found to be 0.204 (r = 0.204, p 0.5).       Conclusion: Since no correlation was found among the results obtained with the two methods, it is concluded that, for assessment of the marginal leakage of dental materials, various methods should be considered.Key words: Tooth Apex, Dye, Electrochemical, Microleakage