Various types of equipment can be used for diagnostic application of ultrasounds in breast lesions and the pictures obtained vary in character according to the nature of the lesion. Circumscribed lesions can be either fluid collections or solid nodules, and it is hoped that technical artefacts still under study will ultimately enable to establish distinction between benign and malignant lesions. Uncircumscribed lesions are characterized by their irregular outline. Echography does not compete with the remaining diagnostic techniques; however, it can be considered as a complementary method in well-defined cases.