A semi-crystalline polyimidesulfone (PISO2) material has been synthesized and characterized. Characterization methods include the thermal analysis of DSC, the measurements of inherent viscosities, the wide angle X-ray diffractions, and the viscoelasticities. The melt flow properties of both amorphous and semi-crystalline samples were also investigated by means of a parallel plate plastometer. This material was found to be not readily recrystallizable at temperatures above its initial peak melting point of 225°C, when compared to other crystalline thermoplastics. This semi-crystalline PISO2 demonstrated a flow about 5 times greater than the amorphous one as characterized by the plastometer. Such enhanced melt flow properties could be of great benefit in the adhesive and composite lamination processes.