Colorants are one of the most important materials used in many industries such as paper, plastic and textile industries. Organic Colorants in the industrial wastewaters can cause serious damages to the environment due to the preventing of light penetration into water, impaired photosynthesis, reducing transfer of oxygen into the water and etc. These compounds are capable to remain in the environment for a long time. In recent years, regulations related color and textile contamination around the world are becoming more stringent. Therefore the importance of dye removal from effluents containing textile dyes has become of greater concern. The most common techniques used for color removal from industrial wastewater, are coagulation, adsorption, ion exchange, filtration, and advanced oxidation processes. In the water and wastewater treatment industry, coagulation is a common process in removing color and Many coagulants are widely used in conventional water treatment processes including inorganic and polymeric coagulants. In recent years because of problems associated with usage of these coagulants including cost and health related issues, there has been considerable interest in the development of usage of natural and inexpensive coagulants. The main purpose of this research is the evaluation expanded perlite of as a coagulant for the removal of textile dyes from aqueous solutions. For this purpose, processed and expanded perlite ore mine Shirin Belagh (2) was obtained from Masoud Factory and used for the experiments. ‌The samples of dye from Acid Blue 113 and Direct Red 23 with different concentrations were prepared and used as the simulated wastewater. In order to optimize the removal efficiency, the experiments with five factors including coagulant dosage, Initial dye concentration, slow mixing rate, slow mixing time and pH were investigated and carried out in batch mode. Full factorial experimental design was used to evaluate the contribution of each of these factors on removal efficiency. Results showed that under optimal conditions, the expanded perlite is capable to remove more than 99% and 98% of Acid Blue 113 and Direct Red 23 respectively. The results from analysis of variance revealed that, all the parameters for both dyes were statistically significant. Studies showed that among four mechanisms of coagulation process, only three of them (electrical double layer condensation,charge neutralization and trapping of falling particles) were effective in coagulation process by the expanded perlite. Overall, this study showed that expanded perlite is capable to removal dyes from aqueous solutions and can be used as an inexpensive alternative for common high cost coagulants in wastewater treatment. Key Words: Acid Blue 113, Direct Red 23, Coagulation and flocculation, Expanded Perlite, Full Factorial.