Two hundred and forty-nine women suffering from breast problems underwent a complete series of tests including clinical examination, mammography, echography, thermography, and fine-needle aspiration (FNA). Ninety-four of these patients were shown to be positive or to have suspected malignancy. Accordingly, they underwent surgical excision followed by histologic examination, while the remaining patients were re-examined after 12 to 18 mo in order to exclude false negatives. The analysis of specificity and sensitivity of every single procedure showed that FNA describes the best degree of sensitivity and specificity but no procedure allows, by itself, the detection of all carcinomas. When considered in combination, clinical examination, mammography, and fine-needle aspiration have a sensitivity of 100% and a specificity of 49%, and are the best diagnostic tests for a correct assessment of mammary lesions. Thermography and echography showed a low degree of sensitivity and should not be included in the routine diagnostic procedure of breast lesions.