In this study, we investigated the adsorption of the cobalt ions from aqueous solutions on zeolite 3A and zeolite 5A. The response surface methodology was used for predictive model building of adsorption process. The concentrations of cobalt ions were measured by UV-Visible spectrometer. Fourier Transform Infrared (FT-IR) spectrum of the fresh zeolites and Co+2 adsorbed zeolites were recorded on FT-IR Spectrophotometer in the range of 4000-400 cm(-1) using KBr disc. The removal efficiencies of cobalt on zeolite were determined. The FT-IR spectrometric studies have been compared with spectrophotometric results.