112 patients with suspected breast lesions were investigated using Scintimammography with 99mTc-MIBI, mammography and magnetic resonance to compare the diagnostic accuracy of Scintimammography with that of mammography and magnetic resonance in the detecting of primary breast cancer. Excisional biopsy was taken after 7-10 days of Scintimammography. 70 patients were diagnosed with breast cancer; 55 palpable and 15 non-palpable lesions, while 42, 30 palpable and 12 non-palpable were diagnosed as benign lesions. The sensitivity of the three methods were high and approximate (89% by Scintimammography, 90% by mammography and 94% by magnetic resonance), while Scintimammography showed higher specificity (86%) versus 21% for mammography and 50% for magnetic resonance. The high specificity in addition to high positive (91%) and negative (82%) predictive values of Scintimammography resulted in a highly accurate diagnostic (87%) method compared to mammography (64%) and magnetic resonance (78%) procedures. Through the complementary use of Scintimammography it is possible to increase the sensitivity for the detection of breast cancer. In patients in whom the status of a palpable breast mass remains unclear, Scintimammography may help to reduce the amount of unnecessary biopsies.