Arsenic poisoning from drinking water has been causing distress to millions of people worldwide due to its toxicity and carcinogenicity. Regardless of numerous long stretches of research, manageable arsenic treatment innovations which are cost-effective in implementation seem to be sporadic. Herein, we demonstrate the facile synthesis of financially savvy rod-shaped carbon coated magnesium oxide (C-MgO) and its characteristic capacity toward arsenite adsorption. With a specific surface area of 117.6 m(2)/g and a controlled mesoporous shell, this material is a better adsorbent than its synthetic counterpart, N-MgO, integrated without a dextrose intervened calcination procedure of precursor. Results show that C-MgO has an adsorption capacity of 142 mg/g at pH 7 after 4 h with an initial As(III) concentration of 80 mg/L. In situ formed easily accessible hydroxyl groups on the surface and porous channels articulate its multilayer chemisorption ability which is empirically well-fitted to the Freundlich isotherm model with an R-2 value of 0.996, while the adsorption kinetics data follows pseudo-second-order kinetics (R-2 = 0.999). In addition, C-MgO has efficient reusability with almost 67% removal efficiency after four cycles. As far as real-time applicability is concerned, 90% of As(III) was adsorbed within 20 min for groundwater As(III) concentrations up to 165 ppb. These qualities give noteworthy innovative perceptions to the utilization of tailored MgO nanoparticles in groundwater purification.