Introduction: Arsenic is known as a carcinogenic compound in drinking water. It can cause acute and chronic effects on human health. In this study, the effect of polyamidoamine dendrimer generation 3 (PAMAM G3) as adsorbents for removal of arsenic (V) from aqueous solutions was evaluated. Materials and Methods: Adsorption experiment was studied in batch system and the effect of different variables such as pH, contact time, concentrations of arsenic and adsorbent dosage on adsorption was studied. Therefore, absorption kinetics and equilibrium isotherms were determined. Results: The results showed that adsorption process is affected by some parameters such as initial concentration, adsorbent dose and contact time. The three models of isotherm including Langmuir, Freundlich and Dubinin- Radeshkuvich were studied while Freundlich and Langmuir isotherms were more compliant with results. Conclusion: According to the results, it can be concluded that adsorption with dendrimer is an appropriate method with high efficiency for arsenic removal from aqueous solutions.