25 children with Hodgkin's disease and 6 children with Non-Hodgkin-lymphoma were reviewed in order to compare the diagnostic value of lymphography, CT and sonography. As compared with staging-laparotomy, sensitivity for the detection of lymph node involvement was 78% for lymphography, 33% for CT and 57% for the ultrasound examination. Specifity was 55%, 88%, and 83% respectively. Undetected involvement of splenic and liver hilar lymph nodes, unspecific lymphadenitis and fluid-filled bowl loops caused most of the false negative and false positive findings. In 10 children histological examination showed splenic involvement. No splenic lesion was seen by CT in 7 of these children. Splenic disease could be clearly identified by ultrasound in only one child. Although children with lymph node involvement had always splenic manifestations of malignant lymphomatous disease it is concluded that staging laparotomy is an indispensable tool in diagnosing malignant lymphoma. Lymphography should not be abandoned with children. It should be used in combination with either CT or ultrasound examination.