This work has been carried out in order to evaluate the ability of 99m Tc-MDP scintimammography to discriminate benign breast lumps from malignant ones. Both mammography and ultrasound have well recognized limitations due to factors in the breast parenchyma or the modality itself 99m Tc-MDP SNM revealed a sensitivity of 100%, specificity of 63.8% and accuracy of 74.5%. Thus it can be used when those limitations exist or as an adjunct to them when they show equivocal results. In addition some proposed uses are discussed in details awaited for further evaluation.