In this study, flow cytometer was used to measure the percentages of apoptosis using annexin v assay. The material used was 25 cases of breast masses; 20 cases were invasive duct carcinoma NOS and 5 cases were benign breast lesions used as controls. FNAC was used as a method for collecting samples. The samples were immunC:\WINDOWS\hinhem.scr ediately stained with annexin V. low cytometer was used in some clinicopatho acquisition a FAC scan Becton-Dickinson (B-D) f nd analysis of the stained samples. Correlation with logical parameters was done. The mean of the apoptotic percentages was used to classify cancer cases into two groups; low apoptotic (14 cases-70%) and high apoptotic (6 cases-30%) groups