Objective: The aim of this study was to observe the level of Endothelin-1 (ET-1), Nitric oxide (NO), and the ratio of ET-1/NO in Erectile dysfunction (ED) and normal subjects. Material & method: This case-control study was carried out in Makassar with subjects recruited from outpatient clinic at Wahidin Sudirohusodo Hospital and divided into 2 groups (56 subjects DE and 34 subjects normal). …