The aim of this study was to analyse the applications and limitations of B-scan ultrasonography for diagnosing fractures of the mandibular condyle and ramus. Thirty-two patients with 39 radiologically proven fractures of the mandibular condyle and ramus were included in the study. The patients were examined with a 7.5 MHz small-part applicator. Five patients without fractures of the facial skeleton acted as controls. Normal sonoanatomical findings had been obtained for patients without mandibular fractures. B-scan ultrasonography enabled the experienced examiner to identify dislocated fractures of the mandibular ramus and the articular process in 67% of the fractures. The main disadvantage of ultrasonography was the inability of this technique to identify non-dislocated fractures. Because of its low sensitivity and specificity, B-scan ultrasonography does not provide an alternative to X-ray diagnosis of mandibular condyle and ramus fractures.