The increasingly widespread use of mammographic screening for breast cancer has induced a considerable increase in the number of surgical biopsies. Fine-needle aspiration and microbiopsies can allow to reduce this number. 1) In patients with nodular densities of benign or indeterminate appearance, a negative fine-needle aspiration indicates that no further investigations are needed. In contrast, complete surgical excision is indicated in cases of stellate images. 2) In patients with potentially malignant microcalcifications, fine-needle aspiration is to little value, and microbiopsies should be performed. Indeterminate (type II or III) calcifications are the best indication, since negative microbiopsies may obviate the need for lumpectomy, if the negative predictive value of microbiopsies is sufficiently high in this indication. Focal suspicious microcalcifications (type IV or V) should be removed surgically for both diagnostic and therapeutic purposes. Type IV or V microcalcifications involving a large area of the breast can be investigated by initial microbiopsy; a positive result allows to recommend immediate mastectomy without prior lumpectomy. Fine-needle aspiration and microbiopsies should be performed as part of a multidisciplinary diagnostic strategy involving radiologists, surgeons, cytopathologists, and pathologists. This approach is the only means of improving the management of non palpable mammographic lesions and of reducing the number of unnecessary operation.