There is a pressing need for more effective appetite-stimulatory therapies for many patient groups including those with cancer. We have previously demonstrated that the gastric hormone ghrelin potently enhances appetite in healthy volunteers. Here, we performed an acute, randomized, placebo-controlled, cross-over clinical trial to determine whether ghrelin stimulates appetite in cancer patients with anorexia. Seven cancer patients who reported loss of appetite were recruited from oncology clinics at Charing Cross Hospital. The main outcome measures were energy intake from a buffet meal during ghrelin or saline infusion and meal appreciation as assessed by visual analog scale. A marked increase in energy intake (31 +/- 7%; P = 0.005) was observed with ghrelin infusion compared with saline control, and every patient ate more. The meal appreciation score was greater by 28 +/- 8% (P = 0.02) with ghrelin treatment. No side effects were observed. The stimulatory effects of ghrelin on food intake and meal appreciation seen in this preliminary study suggest that ghrelin could be an effective treatment for cancer anorexia and possibly for appetite loss in other patient groups.