New aromatic diamines containing phenyl-pendant thiazole units were synthesized in three steps starting from p-nitrobenzyl phenyl ketone. Novel aromatic polyamides containing phenyl-pendant thiazole units were prepared by the low-temperature solution polycondensation of 1,4- (or 1,3-) bis[5-(p-aminophenyl)-4-phenyl-2-thiazolyl]benzene with various aromatic dicarboxylic acid chlorides in N,N-dimethylacetamide. High molecular weight polyamides having inherent viscosities of 0.5-3.0 dL/g were obtained quantitatively. The polythiazole-amides with m-phenylene, 4,4’-oxydiphenylene, and 4,4’-sulfonyldiphenylene units were soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and pyridine, and gave transparent flexible films by casting from the solutions. These organic solvent-soluble polyamides displayed prominent glass transition temperatures (T-g) between 257 and 325 degrees C. On the other hand, the polythiazole-amides with p-phenylene and 4,4’-biphenylene units were insoluble in most organic solvents, and had no observed T-g. All the polythiazole- amides started to decompose at about 400 degrees C with 10% weight loss being recorded at 450-525 degrees C in air.