Due to the increasing concern about the environmental pollution problems, it is so important to perform a number of methods for removing hazardous heavy metals from industrial liquid wastes. Adsorption technique is the most effective and economical one. In the present study, two agricultural by-products namely; cottonseed and soybean hulls, resulting from the oil industry, have been used in the adsorption of thorium element from a wastewater effluent coming from different industries. The results obtained indicate that maximum removal of thorium from a prepared solution takes place at pH 5 where equilibrium was attained after 100 min; using an adsorbent dose of 3 and 3.5 g/L for cottonseed and soybean hulls, respectively. On the other hand, the obtained mathematical data together with the obtained adsorption kinetic parameters indicate that both of cottonseed and soybean hulls could be useful adsorbents for thorium removal from industrial liquid wastes, especially when the low cost, environmental issues and high availability of these materials are considered.