4,4'-Methylenebis(2-tert-butylaniline) was synthesized and reacted with pyromellitic dianhydride to produce a polyimide that showed excellent solubility in conventional organic solvents. Solutions of this polyimide could be cast into transparent, flexible and tough films. The number-average molecular weight, as determined by means of gel permeation chromatography, was 8.9 x 10(4) g/mol and the polydispersity index was 1.97. The glass transition temperature was found to be 217 degreesC. The polyimide did not show appreciable decomposition up to 500 degreesC under a nitrogen atmosphere.