Children on hemodialysis are at increased risk of thrombosis, especially when dialyzed via a central venous catheter (CVC); there are limited published data regarding the safety and efficacy of tinzaparin in this group. We conducted a retrospective chart review of all children in the National Pediatric Hemodialysis Centre for Ireland diagnosed with a CVC thrombus and treated with subcutaneous tinzaparin over a 10 year period. Seven children were treated with subcutaneous tinzaparin for 10 CVC thrombi. Tinzaparin was commenced at 175 IU/kg/day and the dose was titrated by measuring anti-factor Xa levels, aiming for levels of 0.3–1.0 IU/ml. Treatment was continued until resolution of the CVC thrombus. Restoration of normal flows during dialysis occurred within 3 days in all patients. There were no episodes of bleeding and all children tolerated the treatment well.