We use dissipative particle dynamics simulation to study the role of the intramolecular stiffness in the crystallization process of aromatic polyetherimides. We have developed and parameterized a coarse-grained model for polyimides R-BAPB and R-BAPS, which have similar chemical structures but different macroscopic properties. The former one is known as semicrystalline, while the latter one is amorphous. In our model, the only difference between these two polyimides is the intramolecular stiffness. We show that this model can reasonably reproduce the structure formation in polyimide melts. We observe initial stages of crystallization of polyimide R-BAPB while R-BAPS stays amorphous. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1254-1265