Malignant diseases are one of the leading causes of death of children in Europe and America. Over the past decade, there has been a significant progress in diagnosis and treatment, especially in the treatment of leukemia and lymphoma of children. After acute leukemia and brain tumors, lymphomas are in the third place among the most common malignancies in childhood and adolescence, with an annual incidence of 15 per million children under 14 years. Of all lymphoma, mature B non Hodgkin lymphoma (B-NHL) make up 60% of newly diagnosed patients. Two broad categories of lymphoma, Hodgkin’s lymphoma (HL) and non-Hodgkin's lymphoma (NHL), have very different clinical features and therapeutic approach. Despite the numerous discoveries of genetic, immunological and molecular tests in terms of the occurrence of lymph cells, causal factors of the development of lymphoma is still to be determined. Thanks to large multicenter studies and the introduction of new treatment therapies that are adapted to the level of disease (new combinations of cytostatics, radiation, monoclonal antibodyes and bone marrow transplantation), with the aim of optimal risk, acknowledged results in achieving long-term remission and cure were achieved. While the treatment of 'classical' Hodgkin lymphoma exclusively polychemotherapy applied to a specific treatment protocol, at a later stage and with less radiation dose, the NHL applied surgery, radiotherapy, chemotherapy and immunotherapy (monoclonal antibodies). The diagnosis of individual entities B-NHL and thus optimal treatment strategies lie on the quality of morphologic, immunophenotypic, genetic and cytogenetic analysis. In the adult population, a significant reversal in the treatment of B-NHL achieved the Rituximab chimeric monoclonal antibody in combination with CHOP improved the survival rate to 20%. The efficacy of rituximab in the pediatric population has not yet been sufficiently explored. Rituximab in combination with B-NHL-BFM-95 protocol is usually well tolerated and proved to be effective in children and adolescents with B-NHL. It is still debatable whether the NHL children need maintenance therapy achieved remission and whether it would be a therapy with a monoclonal antibody.