Gray-scale B-scan was successful in delineating adrenal masses in 40 patients, all confirmed pathologically. Two patients with extra-adrenal pheochromocytomas, 2 calcified cysts, and 2 patients with bilateral adrenal hyperplasia are demonstrated. The usual ultrasonographic features are presented; they correlated well with urographic, angiographic, CT [computed tomography], and pathological findings. The smallest mass demonstrated was an aldosteronoma (1.3 cm in size).