Refractory angina (RA) is a chronic condition of coronary artery disease (CAD). Endothelial function (EF) measured by flow-mediated dilation (FMD) is an important prognostic marker in CAD. Exercise training is a stimulus that improves EF in CAD. However, exercise training effects on EF in RA are unknown. Therefore, we aimed to verify the effects of exercise training on EF in RA. This was a longitudinal, non-randomized clinical study, involving patients with patients limited by angina, aged 45 to 75years. Patients were prospectively allocated by convenience to either exercise trained (ET) or control group (C). Laboratory analysis, cardiopulmonary exercise test (CPET), and FMD were implemented at inclusion and after 12weeks of exercise training or clinical treatment period. Exercise training included 60minutes per session, 3 times a week, including 40minutes of aerobic exercise on anginal threshold heart rate obtained on the CPET, 15minutes of resistance training, and 5minutes of stretching. A total of 38 patients were included (mean age 60±9years, 22 men); 21 were allocated to the ET and 17 to the C group. Baseline measures showed no differences between groups. After 12weeks glycated hemoglobin and systolic blood pressure were lower in ET before than ET after (p=0.004, and p=0.05, respectively), and exercise time of the CPET was lower in ET before than ET after (p=0.002). Exercise training did not change FMD. In conclusion, exercise training performed on anginal threshold increases exercise tolerance but causes no changes in EF in patients with RA.