The main objective of this study was to assess the feasibility of NIRS (PortaMon®, Artinis Medical Systems) as a noninvasive monitoring method for kidney transplant function. We hypothesized that changes in NIRS (near infra-red spectroscopy) parameters are associated with changes in graft function as estimated by Glomerular Filtration Rate (GFR) based on serum creatinine level. Two cohorts of participants were recruited: Immediate postoperative and those with at least 8 weeks post-transplant. Other inclusion criteria were BMItextless25kg/m2 and AWD (abdominal wall depth) textless2cm. We evaluated 4 patients immediately after the surgery in the operating room and continued the examination every day while they were in the hospital. We also monitored them for 12 weeks after surgery. The second group (16 patients) had their surgery in a median of 26 months prior to their recruitment. The procedure of NIRS monitoring was the same for both groups. We examined the surgical sites and opposite sides of the abdomen as our control for at least 3 minutes each time. The collected data were compared with clinical parameters (BP, e-GFR, and Resistive Index). We analyzed the collected data using linear regression model and we noted a positive significant correlation between the tissue saturation index of the surgical site (TOISS%) and e-GFR adjusted for BMI. We also examined the ∆TOI% (percentage of difference of oxygen saturation index between the surgical site and opposite site) to account for the abdominal muscle effects on collected signals.