Ultrasound (US) findings and accuracy in detecting splenic and hepatic involvement were analysed in 137 unselected, untreated patients with Hodgkin's disease. Histology was available from the spleens of 61 patients and the livers of 59 patients. In 20 patients the spleen appeared abnormal at US; containing focal hypoechoic lesions in 14, being enlarged in 13 and inhomogeneous in 2 patients. Most focal lesions were less than 10 mm. The sensitivity of US in detecting involvement of the spleen was 54% and the specificity 100%; the ability of US to detect hypoechoic splenic lesions improved during the study period. Focal hypoechoic hepatic lesions were found in three patients; histological examination of these showed benign changes in one and suspicious finding in the second. In the third the lesion disappeared during chemotherapy. In three cases with definitive histological evidence of liver involvement, US results were false-negative. The results indicate a higher diagnostic efficacy for US in the detection of splenic than hepatic involvement by Hodgkin's disease.