Lymphadenopathy implies enlarged lymph nodes, without specifically indicating pathology of disorder. It can occur in any age group and is associated with numerous diseases. In majority of cases it is a benign, spontaneously regressing disease, however, minority of patients with lymphadenopathy can have a serious, e.g. malignant disease. This review summarizes current knowledge about etiology of lymphadenopathies, basic methods of examination, indications of lymph node biopsies.