Aim: In this retrospective study, our objective was to evaluate children with arterial or venous thromboembolism, who were treated with tissue plasminogen activator (tPA) in our hospital. Materials and Methods: The medical records of 56 tPA treatments administered to 53 patients with thrombosis in the paediatric intensive care unit and paediatric clinic at Çukurova University, Balcalı Hospital between September 2013 and August 2018, were investigated retrospectively. Results: Thirty-three of the patients were males (58.9%). The median age was 13.5 months (0-203 months). Fifty-two of the patients received low-dose tPA treatment (91.2%) and the mean treatment duration was 63.8±43.3 hours (3-192 hours). Thrombolytic treatment was administered to 38 patients (67.8%) with catheter-related arterial thrombus, to 8 patients (14.3%) with intracardiac thrombus, to 4 patients (7.2%) with pulmonary arterial thrombus, and to 6 patients (10.7%) with deep venous thrombus. No complication was observed in 47 treatments (83.9%). However, 7 patients had minor (12.5%) and 2 patients had major bleeding (3.6%). Recanalization could not be achieved in 8 cases (14.3%) and 4 patients underwent thrombectomy. The use of anticoagulant treatment with tPA did not change the complication rate or the success rate of the recanalization. Conclusion: We determined that low-dose tPA treatment was effective in the treatment of life-, limb- or organ-threatening arterial and venous thromboembolism in children. However, randomized studies with larger sample sizes and control groups are required.