In the diagnosis of breast cancer, noninvasive methods are need in order to detect early stages of this disease. These methods have to have a high specificity in order to discriminate malignant and benign lesions. The scintimammography with 99mTc-MIBI might be such a new method. With this examination the early diagnosis of breast cancer might be improved and may reduce the need for diagnostic biopsies. The aim of our examinations was to get first experiences in comparison with the histological results. The histological results were considered to be the reference method. 25 scintigrafical examinations were evaluated, performed from August 1997 to January 1998. The scintigrafical results were recorded qualitative-visually with a score from 1 to 4. The histological results were received within 1 week after realization of the scintigrafical examination. 22 scintigrafical examinations were evaluated correctly. Of 16 benign lesions 14 were evaluated as true negative and 2 as false positive (fibroadenoma, haematoma). Of the 9 breast carcinomas 8 were evaluated as true positive and 1 false negative (lobular carcinoma in situ). In the case of unselected patients, low numbers of examinations and a diameter of the smallest carcinoma from 1.4 cm a sensitivity of 89% and a specificity of 88% has been observed. Our sensitivity and specificity was in the range of the current international scintimammography-studies. Statements about little breast carcinomas (diameter < 1 cm) are not yet available, because such patients were not examined. The scintimammography is not a screening test. It renders no additional information in the case of clear clinical results and/or clear mammography. Therefore useful indications have to be defined in subsequent scintimammography studies. Possible indications are: palpable breast lesions, which appear normal in mammography, uncertain results in mammography without palpable result and in the follow up of operations of breast cancer without mastectomy. It might be interesting to compare in the future new radiological methods and magnet resonance imaging and positron-emission tomography in the diagnosis of breast cancer with the represented conventional method.