Malignant lymphomas (ML) encompass about 1/6 of all malignant neoplasms. They have been divided into two major categories: Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL). While the classification of Hodgkin's disease is clearly established, classification of non-Hodgkin's lymphomas is still a histopathological problem, and requires a great pathological experience. Many morphological classifications of NHL are used in different countries. In the last few years the "Working formulation for clinical usage" is widely used. Advances in immunology allowed immunological determination of different histopathological lymphoma cell types. Progress in the field of cytogenetics discovered particular cytogenetics abnormalities in patients with different types of NHL. Modern diagnostic procedures in each patient with NHL, besides clinical staging, require a detailed morphological-immunological-cytogenetical (MIC) classification. MIC classification provides the basis for the modern therapeutical management and better estimation of prognosis and evolution of the disease.