Here, a semiempirical method for predicting the solubility limit of polymer solutions at high temperatures is proposed. This method has been developed for infinite-chain-length polymers dissolved in theta solvents. The development is based on several data for polystyrene solutions, and it has been tested also for polyethylene and polypropylene solutions. This method only requires the critical density and temperature of the solvent for the prediction of the high-temperature miscibility limit. The prediction appears to be reasonable considering the simplicity of the correlation model and gives better prediction than earlier comparably simple methods.