The values of ultrasound in differentiation of pathologic processes in the parotid gland were studied in 61 patients. The ultrasound findings were compared with operative and histologic findings. In 28 patients with chronic inflammatory processes, the ultrasound findings were in complete correlation with the histologic findings, showing enlarged parotid glands, homogenous glandular epithelium, and small, multiple cysts. In 31 patients with a tumor of the parotid gland, ultrasound scanning detected the presence of the tumor. In determining the location of the tumor, the method is highly specific when it is localized in the superficial lobe (100%), and it is less specific when it is localized in the deep lobe of the parotid gland. Also, it is highly specific in determination of tumor size (96%). In two cases with retention cysts, the ultrasound findings also correlated with the histologic and operative findings. The results obtained show that ultrasound is a reliable diagnostic method for detection of pathologic changes in the parotid gland.