Background: We aimed to evaluate whether serum apelin could reflect the nutritional status of children on dialysis. Methods: Twelve patients on peritoneal dialysis (PD) and 20 patients on hemodialysis (HD) were enrolled. Patients received individualized diet for six months. Anthropometric and laboratory indices were measured at onset and the end of the study. Results: The anthropometric indices were all significantly lower in patients than in controls whereas similar in PD and HD patients. The protein catabolic rate (nPCR), height, mid-arm circumference (MAC), triceps skinfold thickness (TSF), arm muscle area (AMA) and arm fat area (AFA) z scores were significantly increased in dialysis patients after nutritional intervention. Weight z scores statistically increased in HD group whereas did not statistically change in PD group. Serum albumin levels were significantly improved in PD and HD patients. Apelin levels were similar in PD, HD and control groups. Post nutritional apelin values did not differ in each dialysis groups. On multivariate analysis, apelin was independently associated with age, weight, ESR and TG. Conclusions: Apelin seems to be not a useful indicator for monitoring the nutritional status in children on dialysis. However, the close link of apelin with inflammatory and lipid parameters suggested that apelin might be a novel target for slowing the atherogenic process in pediatric dialysis patients.