For pediatric patients with end-stage renal failure, kidney transplantation is the only treatment that can provide growth and long-term survival. Although rejection is the common cause of renal dysfunction, there are other causes of chronic transplant nephropathy, in which the transplanted kidney develops fibrosis. Hypoxia is considered as possible causes of this order. We used O2-inhalation T2*-BOLD and dual-VENC 4D flow MRI to assess hypoxia in pediatric transplanted kidneys. In patients with chronic transplant nephropathy, hypoxia was found in the renal medulla and small vessel’s flow was reduced. This analysis is an effective means of monitoring hypoxia in transplanted kidneys.