Spleen sarcoma is one of the most rare soft tissue malignancies. The annual incidence is 0.14-0.25/1,000,000 and the average age of diagnosis is 50 to 73 years. The incidence of this cancer has been increasing. Treatment of choice is surgical splenectomy, which rarely gives good results due to the aggressive course of the disease as well as the high potential for metastasis. Overall survival in primary spleen sarcomas as described by various authors is between 4 and 14 months. 80% of patients after spleen rupture do not survive 6 months. We report the case of a 42-year-old male diagnosed with spleen angiosarcoma. The patient underwent surgery in an emergency mode because of rapid rupture of the organ. Due to positive surgical margins, he underwent adjuvant radiochemotherapy followed by chemotherapy. Overall survival time was relatively long (23 months). The international guidelines provide information based on limited data. The role of postoperative radiotherapy in angiosarcomas remains controversial. Postoperative radiotherapy may increase local disease control, especially after nonradical operation, but this does not translate into improvement in overall survival time of these patients. The case shows that adjuvant radiotherapy as part of cancer treatment strategy may prolong the overall survival.