A hybrid silica mesoporous material with l-glutathione (LG) (SG-LGPS) was synthesized by a modified sol–gel process. The chemical and structural characterization of the SG-LGPS material was achieved by Fourier transform infrared, solid-state 13C and 19Si NMR, and X-ray diffraction. Surface analysis showed a specific surface area of 466.8 m2 g–1. X-ray photoelectron spectroscopy and energy dispersive X-ray spectrometry measurements demonstrated the chemical composition of the hybrid material and the presence of As­(V) after the uptake process. The adsorption performance for SG-LGPS reached a maximum arsenic uptake of 45.22 mg g–1 at pH = 4; kinetics and equilibrium results were better described by the pseudo-second-order and Temkin models, respectively. Competitive ion adsorption studies were also performed. The uptake mechanism proposed for this material is a bidentate arsenic–glutathione complex. The present material proposed is as follows: (1) a new scope for environmentally friendly materials with amino acids and (2) a versatile adsorption application extended to other heavy metal ions due to the LG functional group composition.