Thromboembolic events in preterm neonates are increasingly being diagnosed due to the increasing use of umbilical catheters and central venous catheters. Whether thromboembolic events should be treated routinely with low-molecular-weight heparin (LMWH) is controversial and the optimal management is still not clear due to the lack of randomized controlled trials. Most importantly, knowledge about the safety of treatment with LMWH in neonates with thromboembolic events is very limited. We present a case of severe hemorrhage in a preterm neonate after LMWH treatment and summarize the scarce data reported in the literature.