Cardiovascular diseases are the leading cause of death globally which usually begins with endothelial dysfunction. This vascular abnormality is potentially caused by one kind of heavy metal called cadmium (Cd). Vitamin C, as an antioxidant, can serve as the free radical scavenger. This research aimed to determine the effect of vitamin C on the viability of endothelial cells and endothelial dysfunction through nitric oxide (NO) levels and malondialdehyde (MDA) in human umbilical vein endothelial cells (HUVEC) induced with CdCl 2. HUVEC was induced by 24.154 µg/L CdCl 2. Three treatment groups of CdCl 2-induced HUVEC were employed, each given vitamin C concentrations of 50, 100, and 200 µM, respectively. Cell viability was assessed by MTT assay. Levels of NO and MDA were determined by with the calorimetric test. Cell viability was increased significantly in treatment group receiving vitamin C 100 and 200 µM. However, there were no significant differences on NO and MDA levels in vitamin C treatment groups compared to control. In conclusion, vitamin C increases endothelial cell viability and NO level, and reduces MDA levels in CdCl 2-induced HUVEC. This study implies the importance of vitamin C supplementation to prevent cardiovascular diseases.