This case is presented to emphasize the EDTA-dependent PTP (pseudothrombocytopenia) that should be considered as a possible cause of low platelet count and evaluate the effect of different anticoagulants on complete blood count (CBC). The CBC and blood smears, of the patient who was been thought to have pseudothrombocytopenia, were performed in blood samples with EDTA, sodium citrate and lithium heparin. The platelet counts obtained from blood samples containing EDTA decreased over time. However, platelet counts in blood samples containing citrate and heparin were within the reference range. Platelet clumps were found in the blood smears from blood samples containing EDTA. There was no apparent change except platelet, leukocyte counts and platelet indices. EDTA-dependent PTP should be considered in the presence of pseudothrombocytopenia. In such cases, dilution factor should be considered for leukocyte, erythrocyte, platelet counts, platecrit, hemoglobin ve hematocrit values repeated in blood samples with citrate.