A series of novel poly(aryl prehnitimide)s based on diphenylprehnitic dianhydride (5,6-diphenylbenzene-1,2,3,4-tetracarboxylic dianhydride) are synthesized and characterized. Polyimides having intrinsic viscosities of 0.45-1.81 dL/g in N-methyl-2-pyrrolidinone were obtained by one-step solution polymerization in m-cresol. These polyimides are readily soluble in many common organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethyl sulfoxide, and N,N-dimethylformamide. The poly(aryl prehnitimide) derived from m-phenylenediamine is also very soluble in tetrahydrofuran, pyridine, and chloroform. Glass transition temperatures were in the range of 362-443 degrees C, as determined by differential scanning calorimetry and thermomechanical analysis. Degradation temperatures for 5% weight loss occurred all above 483 degrees C in nitrogen and 449 degrees C in air. Young’s moduli of thin films for some polyimides ranged from 2.07 to 3.94 GPa as assessed by thermomechanical analysis.