Ultrasonographic examinations of salivary glands were performed on 24 patients with Sjögren's syndrome. On B-mode echographic images, the submandibular glands of 21 of the patients (88%) showed a heterogeneous pattern, whereas all of the control subjects had homogeneous patterns. This distinction was further confirmed by the results of the analysis of the histogram patterns of echo intensity and echo frequency of the submandibular glands, which showed that the width of the echo level at 0% and 10% of the maximum normalized frequency was significantly greater in patients with Sjögren's syndrome than in the control subjects. Similar histographic findings were present in the parotid glands, although the heterogeneous ultrasonographic pattern was observed in only 8 of the 24 patients (33%). These results indicate that ultrasonography may be useful in the evaluation of salivary gland involvement in patients with Sjögren's syndrome.