Since multiple primary malignant tumors are rare in children, their presence can be a diagnostic and therapeutic problem. In this report, we present a six-year-old boy with Langerhans cell histiocytosis and Hodgkin's disease. On admission, the patient had lytic lesions and a periosteal reaction on the left trochanter major from which an open bone marrow biopsy was performed. The biopsy revealed Langerhans cell histiocytosis. Eight months later, the child presented with enlarged left cervical lymph nodes and the biopsy demonstrated Hodgkin's disease. Although there was an eight-month interval between the two histopathological diagnoses, the diffuse pulmonary parenchymal infiltration observed on the first admission, was later confirmed by an open-lung biopsy as Hodgkin's disease. The patient was said to have two concurrent lymphoreticular malignancies. To our knowledge, this is the youngest case reported with this association in the English language literature.