Obesity can cause enlargement and increase in the number of adipose cells in the body as well as a decrease in adiponectin levels. Adiponectin is an anti-inflammatory cytokine. Obesity is also associated with vascular endothelial dysfunction, which is caused by reduced nitric oxide (NO) availability, as a result of increase production of oxidative stress. This study aims to determine the effect of ethanol extract of rosella flowers (Hibiscus sabdariffa Linn) on adiponectin levels and serum NO levels in animal models of fructose-induced obesity. The research method was using a Post Test Only Control Group Design, using male Wistar rats for 60 days. This study consisted of 6 groups, namely the normal group (normal diet), the induction group (normal diet + fructose 60%), the comparison group (normal diet + fructose 60% + orlistat), and 3 test groups (normal diet + fructose 60% + ethanol extract of rosella flowers 125 mg/ kgBW, 250 mg/kgBW and 500 mg/kgBW). The results show that the ethanol extract of rosella flowers has a reducing effect on body weight and increases serum adiponectin and NO levels. In conclusion, ethanol extract of rosella flowers at a dose of 250 mg/kgBW can increase adiponectin levels and a dose of 500 mg/kgBW is the best dose in improving endothelial dysfunction.