Disperse dyes derived from heterocyclic compounds such as pyridone, diaminopyridine, carbazole, and 2-phenylindole, have been known to possess high light fastness. Four heterocyclic azo disperse dyes were synthesized by using three diaminopyridines and 2-phenylindole as coulping components and their dyeing and fastness properties were compared with an aminoazobenzene disperse dye. The wavelengths of maximum absorption of the synthesized heterocyclic dyes were in the range of 508-528 nm. The molar extinction coefficients of dyes having diaminopyridine were higher than that of an aminoazobenzene disperse dye. The dyes derived from aminopyridine having phenyl group exhibited poor to moderate build-up compared to the aminoazobenzene dye. Wash, light, heat and rubbing fastnesses of heterocyclic azo disperse dyes were good to excellent. The light fastness was improved by 0.5-1 grade by the addition of a UV absorber.