Dietary nitrate supplementation, which improves skeletal muscle oxygen utilisation, vascular endothelial function and exercise capacity in people with chronic obstructive pulmonary disease, may benefit other lung conditions. In a double-blind, placebo-controlled, crossover study, in 19 adults with Group 3 pulmonary hypertension who desaturated during exercise, 140 mL of nitrate-rich beetroot juice improved endurance shuttle walk time compared with nitrate-depleted beetroot juice placebo (median (IQR) ESWT NR-BRJ 197 (140–273) s vs PL-BRJ 174 (107–229) s; median difference (MD) (95% CI) 30 (6.19 to 91.07) s, p=0.0281), endothelial function, flow-mediated dilatation (+3.40±5.47% vs −1.33±4.78; MD (95% CI) 4.73 (1.44 to 8.02), p=0.007) and lowered mean arterial blood pressure (−3.9 (−7.4 to −0.4) mm Hg, p=0.028).