Ethylenediaminetetraacetic acid (EDTA) can cause complexes with radioactive cations during decontamination operation in the nuclear industry, which results in impeding the treatment of decontamination wastes by conventional treatment processes such as chemical precipitation and ion exchange and may be potentially dangerous to the environment. To achieve efficient removal of EDTA from aqueous solution, mesoporous Al-MCM-41 molecular sieves (Si/Al = 25, 50, 75, and 100) were synthesized hydrothermally, characterized by XRD, N-2 adsorption studies, and TEM, and evaluated through an adsorption process. Adsorption of EDTA over Al-MCM-41 shows the applicability of Freundlich and Langmuir isotherms. Al-MCM-41, at Si/Al = 25, has proved to be a better adsorbent than its other ratios and commercial adsorbents such as activated charcoal and H beta zeolite. Retainment of crystallinity of Al-MCM-41 after desorption has been achieved in this study.