As a result of industrial development water pollution has become a major issue. Providing clean water of sufficient quality and quantity is essential. According to literature, 100 000 different dyes are used worldwide in the printing, food and textile industries. Remazol Brilliant Violet-5R belongs to the group of azo dyes used in the textile industry. The purpose of this paper is to study the removal of anionic dye RBV-5R using calcined eggshell. We investigated the effect of initial dye concentration (20-100 mg/L RBV-5R), biomass amount, contact time, temperature, and pH on the adsorption process. We calculated the amounts of adsorbed material in equilibrium and the efficiency of the adsorption process. Various studies were performed on the adsorption process and the adsorbent morphology (EDX, SEM, FTIR, Raman), as well as isotherm (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich), kinetic and diffusion models were used to characterize the process. Calcined eggshell was also characterized by thermogravimetric, BET surface methods. Based on the results obtained, it can be said that the calcined eggshell can be used effectively to remove the dye from the aqueous solution.