Anorexia and malnutrition confer significant morbidity and mortality to patients with end-stage kidney disease but are resistant to therapy. The aim of this study was to determine whether subcutaneous administration of ghrelin, an appetite-stimulating gut hormone, could enhance food intake in patients who are receiving maintenance peritoneal dialysis and have evidence of malnutrition. The principal outcome measure was energy intake during a measured study meal. Secondary outcome measures were BP and heart rate and 3-d food intake after intervention. Nine peritoneal dialysis patients with mild to moderate malnutrition (mean serum albumin 28.6 +/- 5.0 g/L, total cholesterol 4.4 +/- 0.6 mmol/L, subjective global assessment score of 5.7 +/- 1.7) were given subcutaneous ghrelin (3.6 nmol/kg) and saline placebo in a randomized, double-blind, crossover protocol. Administration of subcutaneous ghrelin significantly increased the group mean absolute energy intake, compared with placebo, during the study meal (690 +/- 190 versus 440 +/- 250 kcal; P = 0.0062). When expressed as proportional energy increase for each individual, ghrelin administration resulted in immediate doubling of energy intake (204 +/- 120 versus 100%; P = 0.0319). Administration of ghrelin maintained a nonsignificant increase in energy intake over 24 h after intervention (2009 +/- 669 versus 1579 +/- 330 kcal) and was not followed by subsequent underswing (1790 +/- 370 versus 1670 +/- 530 and 1880 +/- 390 versus 1830 +/- 530 kcal on days 2 and 3, respectively). Ghrelin administration resulted in a significant fall in mean arterial BP (P = 0.0030 by ANOVA). There were no significant adverse events during the study. Subcutaneous ghrelin administration enhances short-term food intake in dialysis patients with mild to moderate malnutrition.