The aim of our study was to assess the diagnostic value of neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and red blood cell distribution width (RDW) in children with lymphadenopathy (LAP). METHODS: Between January, 2009 and December, 2018, 190 children who underwent excisional lymph node biopsy due to enlarged lymph nodes were included. The clinical and laboratory features of pediatric patients with lymph node enlargement, histopathological examination of the lymph node, and the role of complete blood count parameters in the differentiation of reactive and malignant LAP were analyzed retrospectively. RESULTS: In total, 139 (73.2 %) children had pathologically confi rmed reactive LAP and 51 (26.8 %) were diagnosed with lymphoma. Compared with the reactive LAP group, median values for NLR, MLR, PLR, and RDW were signifi cantly higher in children with lymphoma (p < 0.01). According to receiver operating characteristic curve analysis performed for distinguishing between reactive LAP and lymphomas, the area under curves of NLR, MLR, PLR, and RDW were 0.75, 0.76, 0.71, and 0.61, respectively. CONCLUSIONS: Children with histologically proven lymphoma have higher NLR, MLR, PLR, and RDW values than children with reactive LAP. NLR, MLR, PLR, and RDW tests, which can be performed even in primary health care centers, may be useful markers to determine which patients with LAP should be referred to the advanced center at an early stage for biopsy (Tab. 4, Fig. 2, Ref. 26).