Spontaneous retroperitoneal hematoma refers to bleeding of the retroperitoneal space without prior trauma or iatrogenic injury. Its diagnosis is often delayed due to a nonspecific clinical presentation. This case-series presents three patients with spontaneous retroperitoneal bleeding. Patient A presented with a spontaneous bleeding around the right iliopsoas muscle due to antiplatelet medication and was managed conservatively. Patient B had a spontaneous arterial bleeding near the right kidney, subsequently determined to be associated with a pheochromocytoma. Endovascular treatment successfully stopped the bleeding. The pheochromocytoma was resected during follow-up. Patient C had a spontaneous rupture of the left iliac vein with a concomitant deep vein thrombosis. She underwent emergent laparotomy, but unfortunately did not survive. This case-series emphasize the diverse presentation, varied causes, and different treatment strategies for spontaneous retroperitoneal hematoma. Timely diagnosis is hard, but crucial to enable an individualized treatment.