The authors describe the US patterns of normal small-joint tendons and of soft-tissue masses, together with the inflammatory and traumatic changes in tendon echogenicity. The relationship of small-joint tendons to surrounding structures is also reported. Sixteen patients aged 1-60 years were examined. The indications for US examination were: pain, impaired motion, or evidence of a palpable mass. The normal contralateral region was always studied for comparison. US showed 13 pathologic conditions and 3 normal patterns. 6 patients underwent surgery, while the other 10 were treated by medical therapy. US diagnosis was confirmed in 15/16 cases (13/13 pathologic conditions and 2/3 normal patterns); surgery demonstrated a partial tendon rupture in the only false negative at US. Sonography proved thus useful also in the imaging of small-joint tendons. This technique, which demonstrates normal and pathologic tendon patterns, helps make a correct diagnosis and plan the appropriate treatment.