Discharge of untreated chromium containing tannery wastewater into the environment poses arnserious environmental and health problem. Finding an environmentally safe and cost effectivernmethod which is efficient enough to meet the regulatory standards of industrial wastewaterrndischarge presents unique challenges. There is need for environmentally friendly and cost effectivernmethods for their removal. The present study investigated the adsorptive removal of chromium ionsrnfrom Ethiopian tannery share company site using thermally modified chicken eggshells because it isrnhigh removal capacity, low cost and easy accessibility. Characterization of the adsorbent such asrnproximate analysis, surface charge, Fourier transform infrared radiation spectroscopy, surface arearnand X- ray diffraction was done prior to bio sorption process. Thermally modified eggshell wasrnassessed in batch mode adsorption experiment for percentage chromium removal and milligramsrnper gram chromium uptake as a function of contact time, pH, and dose of the adsorbent and initialrnconcentration. The effect of factors such as one factor effect and interaction effects wererninvestigated by central composite design (CCD). The maximum percent removal was obtainedrn99.505 % at optimum pH =7, adsorbent dose=1g/100ml, contact time 120min and 80mg/L of initialrnchromium ion concentration. Sorption kinetics of chromium adsorption by Thermally modifiedrneggshell was predicted reliably using a pseudo-first order, pseudo-second order and intra particlerndiffusion model. The kinetic adsorption data well fitted to pseudo-second order. Equilibriumrnuptakes were evaluated using Langmuir, Freundlich and Temkin adsorption isotherm models. Thernequilibrium data well fitted into Langmuir isotherm. The study demonstrated the efficacy ofrnThermally modified chicken eggshells and presents it as a viable low-cost adsorbent forrnbioremediation.