Lumbar puncture (LP) and intrathecal chemotherapy (IT CT) are common procedures and treatment options for hematologic patients. Although they can also be used in thrombocytopenic patients, there is no consensus on the safe cutoff value of platelet counts for LP and IT CT practices. This research aimed to determine the safety of LP and IT CT administration in thrombocytopenic patients using different cutoff platelet values. One hundred and fifty-two adult patients who had LP indications were evaluated. Among them, 42 patients received IT CT. The cerebrospinal fluid results from 100 procedures were available. The preprocedural platelet count was <100.000/mm3 and <50.000/mm3 in 41 (41 %) and 18 (18 %) patients, respectively. Ten of these patients received platelet transfusion prior to LP. In the untransfused group, the platelet count was <50.000/mm3 in 12 (12 %) patients, among whom seven patients had a platelet count of <30.000/mm3. The traumatic tap was comparable among the transfused and untransfused groups (p = 0.632). No correlation was observed between the thrombocyte value and the traumatic tap (p = 0.891). The ratio of the traumatic tap was not significant between the patient groups with a platelet count of ≥50.000/mm3 or <50.000/mm3 (p = 0.418). After adding the transfused patients, the traumatic tap ratio remained nonsignificant between the two groups (p = 0.851). Hemorrhagic complications were rare in the thrombocytopenic patients who received IT CT after the LP procedure applied by experienced specialists. However, further prospective large studies evaluating the safety of procedures in thrombocytopenic patients are needed to make clear conclusion. Copyright © 2020. Published by Elsevier Ltd.