Since coronavirus disease 2019 (COVID-19) is associated with a hypercoagulable state, especially in critical patients, anticoagulation is used for thromboprophylaxis. Hemorrhagic complications, even uncommon ones such as retroperitoneal hemorrhage, can occur following anticoagulant administration. We present 5 patients with COVID-19 whose clinical course was complicated by spontaneous retroperitoneal hemorrhage. The patients were initially presented with respiratory manifestations of the infection. There was no history or evidence suggestive for traumatic injury. After hospitalization, the patients received supplemental oxygen, antibiotics, enoxaparin or heparin, interferon beta-1b (in three patients), and anticoagulation with subcutaneous injection of enoxaparin (three patients) or heparin (two patients). During the course of hospitalization, the patients showed sudden-onset abdominal pain (three cases), hypotension (three cases), and an acute drop in hemoglobin level. CT scan of the abdomen and pelvis revealed retroperitoneal hemorrhage. For one patient, owing to unstable vital signs and an expanding hematoma, surgical intervention was performed. Others were managed conservatively with discontinuation of anticoagulants, intravenous (IV) fluid resuscitation, and packed red blood cells transfusion. Three patients died due to worsening of the infection and respiratory failure. Retroperitoneal hemorrhage could be a potential complication in COVID-19 patients receiving anticoagulation. Careful monitoring of the vital signs and blood tests like hemoglobin level of such patients is essential.