In this work the solubility of two polymorphic forms A and B of erlotinib hydrochloride in isopropanol (IPA) and acetone were determined by means of high-performance liquid chromatography (HPLC) in the temperature range from (273.15 to 303.15) K. The experimental data were correlated with the modified Apelblat equation. In particular, the effect of the surfactant Tween 80 on the solubility of both polymorphs was studied as well. The results show that the solubility of both polymorphs generally increases with the temperature, and polymorph A has a higher solubility than polymorph B which indicates that polymorph A is the metastable form. The modified Apelblat equation shows a good agreement with the experimental data with a percent error less than 3 %. Furthermore, the solubility of both polymorphs increases in a linear fashion with increasing the content of Tween 80 in organic solvents, wherein Tween 80 presents a same solubilization capacity to both polymorphs and a higher solubilization capacity in acetone than in IPA.