The NOCTET (NOrdic Certican Trial in HEart and lung Transplantation) trial demonstrated that everolimus improves renal function in maintenance thoracic transplant recipients. Nevertheless, switch to everolimus is not recommended for patients with advanced renal failure. We evaluated NOCTET data to assess everolimus introduction amongst thoracic transplant recipients with advanced renal failure.In this 12-month multicenter Scandinavian study 282 maintenance thoracic transplant recipients were randomized to everolimus with calcineurin inhibitor (CNI) reduction (56% reduction in CNI exposure achieved) or standard CNI therapy. GFR was measured at baseline and 1-year using Cr-EDTA clearance.In patients with baseline GFR <30 ml/min (n=21) renal function improved in the everolimus group (Δ GFR 6.7±9.0) as compared to the control group (Δ GFR −1.6±5.1) (p=0.03). Amongst patients with moderate renal impairment (GFR 30-59 ml/min; n=173) renal function improvement was also greater amongst everolimus patients as compared to controls (Δ GFR 5.1±11.1 versus −0.5±8.7 ml/min, respectively; p<0.01), while in patients with GFR>60 ml/min the effect was more modest. Time since transplant was a mediating factor as GFR improvement was limited to patients with time since transplant < median value of 4.6 years.Conversion to everolimus and reduced CNI significantly improves renal function amongst maintenance thoracic transplant patients with pre-existing advanced renal failure. This beneficial effect is limited to patients undergoing conversion less than 5 years after transplant indicating a “window of opportunity” that is appropriate for pharmacological intervention with everolimus.