Abstract: Chondrocytes in avian growth cartilage undergo proliferation, hypertrophy and then die by a mechanism that has widely been described as apoptosis. The aim of the current study was to investigate the morphology of dying hypertrophic chondrocytes in duck and quail growth cartilage. Growth cartilage from post-hatching growing ducks and quail was fixed in 10% formalin or 5% glutaraldehyde and processed for light and electron microscopic examination. Growth cartilage from ducks and quail was similar to other avian species; the chondrocytes were organized into three zones; resting, proliferative and hypertrophic. Ultrastructural studies of the tissue specimens from ducks and quail suggested that there were two morphologically different types of hypertrophic chondrocytes; hypertrophic dark chondrocytes with electron-dense cytoplasm and hypertrophic light chondrocytes with electron-lucent cytoplasm. Dark and light hypertrophic chondrocytes were dying by mechanisms morphologically different from apoptosis. Dying hypertrophic dark chondrocytes appeared to undergo extrusion of their contents into the extracellular matrix. Whereas, dying hypertrophic light chondrocytes appeared to disintegrate within the cell membrane. No a typical example of apoptotic death of hypertrophic chondrocytes was observed at any stage of development. From the observations presented in this study, it was concluded that dark and light hypertrophic chondrocytes appeared to be different cell populations with different morphology. These cells showed non-apoptotic physiological modes of death. For improving production, further understanding growth and mechanisms of bone and cartilage diseases in avian, the results reported here should be considered.