Background: Angiosarcoma (AS) and Kaposi sarcoma (KS) are rare malignant and borderline malignant vascular tumors that may first present to a dermatologist. There are few Korean studies that particularly focus on their survival due to low incidence. Objective: To investigate the survival and prognostic factors among patients with AS and KS, in addition to their clinical features. Methods: Between 2000∼2021, medical records of 26 AS and 26 KS patients at a single center were analyzed retrospectively. Additionally, we calculated the disease specific survival (DSS) and overall survival (OS) of two diseases. Results: The mean age of patients with AS was 72.9 years and 67.3 years for KS. The most common tumor location was the scalp in patients with AS (80.8%) and the foot (65.4%) in those with KS. In patients with AS, 1-year DSS and OS rates were 36.0% and 34.6%, respectively. Five-year DSS and OS rates were 24.0% and 20.2%, respectively. In patients with KS, the 1-year DSS and OS rates were 96.2% and 84.6%, respectively. The 5-year DSS and OS were 91.6% and 58.0%, respectively. Patients who were older or had larger lesions than average had decreased DSS and OS in AS. Among the patients with KS, immunosuppressed status, including human immunodeficiency virus infection, showed reduced OS. Conclusion: Apart from confirming grave survival of AS and favorable survival of KS, patient’s age and size of lesion affect survival outcomes in patients with AS. Otherwise, immunosuppressed status affects survival outcomes in patients with KS. (Korean J Dermatol 2023;61(8):472∼480)