The effects of gamma irradiation on a lignocellulosic biosorbent—coir pith were studied in view of its utilization for separation of metal ions of nuclear importance. The biosorbent was irradiated up to a dosage of 3.6MGy using a ⁶⁰Co source. Physicochemical changes induced by γ irradiation in coir pith, were investigated using fourier transform infrared spectroscopy, thermogravimetric and differential thermal analysis. Irradiation in air had negligible effect on the chemical structure of coir pith. However, irradiation in aqueous medium partially altered the chemical linkages in coir pith; which reflected in marginal decrease in its sorption capacity for strontium.