PURPOSE: To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. SUBJECTS AND METHODS: Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evalvated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on tenmammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquiries were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. RESULTS: Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for truemicrocalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hypendense dots was more superficial in subcutaneous fat (seven cases) and subareolar area(six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated byopen drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. CONCLUSION: These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy.