Background <p>Juxta-articular giant cell tumors in the talus are very rare and pose a special problem for reconstruction after aggressive tumor curettage. Currently, vascularized iliac bone graft (VIBG) has proven to improve the outcome of partial talus defect, however, technical difficulty occurs when both the three-dimensional fitting for a large cavity and structural support to the articular surface in the talus are needed. Prior publications have demonstrated that the three-dimensional printing technology can improve surgical efficiency on the vascularized bone graft for extremity and mandibular reconstructions in complex clinical scenarios.</p> Case presentation <p>We report the case of a Campanacci grade III giant cell tumor of the right talus, involving the subchondral bone close to four articular surfaces and extending into the medial soft tissue. The tumor was successfully managed with a downgrading strategy that combined microwave ablation and curettage, followed by reconstruction via a VIBG guided by a three-dimensional printed model. Computed tomography scans confirmed bone union at two months postoperatively. Two years after surgery, collapse of the articular surface or evidence of recurrence or osteonecrosis was not observed. The patient achieved a normal gait with 15 degrees of ankle dorsiflexion and 45 degrees of plantar flexion under weightbearing conditions.</p> Conclusion <p>The reconstruction of the large residual cavity in the talus with a VIBG after microwave ablation and aggressive tumor removal of giant cell tumor under the guidance of a three-dimensional printed model enabled the preservation of the ankle function.</p>