In this study, the variation in surface morphology of copper phthalocyanine (CuPc) thin films treated with a flow of acetone vapor assisted by nitrogen carrier gas was investigated. The CuPc nanorods with similar dimensions were well dispersed throughout the whole film surfaces after ~20 min. of treatment. However, the electronic absorption spectra only changed slightly, which indicates that molecular stacking was not altered during treatment. This treating method is simple and more advantageous compared to other solvent treating technologies such as mixed solvent spray treatment using organic solvents and water since it requires relatively mild treating conditions and does not need the presence of water.