One hundred children with non-Hodgkin's lymphoma (NHL), 80 boys and 20 girls, ranging in age from two to 15 years (median five years), were seen at the King Faisal Specialist Hospital and Research Centre over a period of five years (1976)(1977)(1978)(1979)(1980)(1981). This constituted 17 percent of all childhood malignancies seen at this Hospital during the same period. Abdominal pain, anorexia, and weight loss were the most frequent presenting complaints. The primary sites of initial involvement included: abdomen in 79 patients, mediastinum in 11 patients, long bones in two patients, neck and skin in one patient each, and undetermined in six patients. According to histologic classification, the following subtypes were seen: lymphoblastic, 11 cases; undifferentiated non-Burkitt's, 67 cases; undifferentiated Burkitt's, 17 cases; histiocytic, four cases; and Mediterranean lymphoma, one case. The most useful diagnostic radiographic procedures were sonography of the abdomen and chest radiography. The Burkitt's lymphoma demonstrated space-time clustering but other forms of lymphoma showed rather uniform distribution. The results of this study indicate that childhood NHL is more common in Saudi Arabia than in Europe and in the United States, that it occurs at a much younger age, and that it shows the predominance of the abdominal form.