Background-There is evidence that aerobic exercise improves functional capacity in patients with New York Heart Association (NYHA) class II and III chronic heart failure. However, it is unknown whether dancing is safe and able to improve functional capacity in patients with chronic heart failure. Methods and Results-We prospectively studied 130 patients with stable chronic heart failure (107 men; mean age, 59Ϯ11 years) in New York Heart Association class II and III and left ventricle ejection fraction Ͻ40%. Patients were randomized to supervised aerobic exercise training at 70% of peakVO 2 3 times a week for 8 weeks (group E, nϭ44) or to a dance protocol of alternate slow (5 minutes) and fast (3 minutes) waltz lasting 21 minutes (group D, nϭ44). A group that did not undergo exercise training served as control (group C, nϭ42). On study entry and at 8 weeks, all patients underwent cardiopulmonary exercise testing on a cycle ergometer until volitional fatigue, 2D-echo with Doppler, and endothelium-dependent dilation of the brachial artery. Heart rate was 111Ϯ15 bpm during exercise training and 113Ϯ19 bpm during dancing (Pϭ0.59). PeakVO 2 , anaerobic threshold,VE/VCO 2 slope, andVO 2 /W slope were all similarly improved in both E and D groups (ϩ16% and 18%, 20% and 21%, 14% and 15%, 18% and 19%, respectively; P not significant for all comparisons; PϽ0.001 versus controls). Endothelium-dependent relaxation was also similarly improved (group E, from 2.6Ϯ1.3% to 5.2Ϯ1.5%, PϽ0.001 versus control; group D, from 2.2Ϯ1.4% to 5.0Ϯ1.5%, PϽ0.001 versus control for both E and D). The change in peakVO 2 in E and D groups was correlated with changes in peak velocity of early filling wave/peak velocity of late filling ratio (rϭϪ0.58, PϽ0.001) and endothelium-dependent dilation (rϭ0.64, PϽ0.001). Untoward events were rare in both E and D groups. Conclusions-In patients with stable chronic heart failure, waltz dancing is safe and able to improve functional capacity and endothelium-dependent dilation similar to traditional aerobic exercise training. Waltz dancing may be considered in clinical practice in combination with aerobic exercise training or as an alternative to it. (Circ Heart Fail.