In order to investigate the involvement of apoptosis in the pathogenesis of aplastic anemia, we determined the proportion of apoptotic cells in paraffin embedded bone marrow biopsies from patients with aplastic anemia, using [TUNEL] staining solution. The cases are divided into two groups according to bone marrow cellularity. Correlation between apoptotic index and each of the haematological data was of no significance. Comparison between the haematological data of the two groups showed no significant difference except between apoptotic indexes which was highly significant. In conclusion apoptosis plays a role in the pathophysiology of aplastic anemia, yet could not be considered as the main pathological cause of the disease.