Background <p>Early mobilization is recommended to improve postoperative recovery, yet implementation after kidney transplantation is often delayed or limited.</p> Objectives <p>To determine whether a transfer- and ambulation-focused early mobilization protocol improves early postoperative exercise capacity and mobilization in kidney transplant recipients(KTRs), and to evaluate its safety and feasibility.</p> Methods <p>Single-center, randomized, parallel-group controlled trial conducted at West China Hospital, Sichuan University (Chengdu, China). Fifty-four adults undergoing kidney transplantation were randomized 1:1 postoperatively to usual care (control group) or usual care plus an early transfer- and ambulation-focused mobilization protocol (early mobilization group, EMG). The primary outcome was the 6-minute walk distance (6-MWD) on postoperative day(POD) 7; secondary outcomes included 6-MWD change from baseline, grip strength, grip strength change from baseline, laboratory indices, prespecified safety and feasibility endpoints, postoperative complications, and hospital length of stay.</p> Results <p>Baseline characteristics were comparable between groups. Compared with CG, EMG achieved shorter bed rest time, better 6-MWD (with a smaller postoperative decline from baseline where available), and lower white blood cell (WBC) count on POD7 (all <i>p</i> &lt; 0.05). No participant in EMG was graded as “unable to complete” the mobilization protocol, and no protocol-related adverse events were observed.</p> Conclusions <p>A transfer- and ambulation-focused early mobilization protocol improved early postoperative functional capacity and mobilization in KTRs and appeared safe and feasible.</p> Trial registration <p><a href="http://www.chictr.org.cn">http://www.chictr.org.cn</a> ChiCTR2400086546(07/04/2024).</p>