Background: The advancement of 3D printing technology has allowed for the use of custom-designed implants for difficult-to-treat foot and ankle pathologies. This study reports on the radiographic and functional outcomes of a case series of patients treated with patient-specific 3D-printed titanium implants. Methods: Fifteen consecutive patients treated with custom-designed 3D-printed implant cages for severe bone loss, deformity correction, and/or arthrodesis procedures were included in this study. A minimum of 1 year of clinical and radiographic follow-up was required. No patients were lost to follow-up. Patients completed a visual analog scale for pain, the Foot and Ankle Ability Measure Activities of Daily Living score, and the American Orthopaedic Foot & Ankle Society Score outcomes questionnaires preoperatively and at most recent follow-up. All patients had postoperative radiographs and computed tomography (CT) scans to assess bony incorporation. The mean age was 53.3 years (range, 22-74 years) with a mean follow-up of 22 months (range, 12-48 months) for these 15 patients. Results: Radiographic fusion verified by CT scan occurred in 13 of 15 patients. There was significant improvement in pain and all functional outcome score measures. All patients who went on to fusion were satisfied with their surgery. There were 2 failures, consisting of 1 infection and 1 nonunion, with an overall clinical success rate of 87%. Conclusion: These patients demonstrated the successful use of patient-specific 3D-printed titanium implants to treat complex large bony defects, deformities, and arthrodesis procedures. These implants offer surgeons a novel and promising approach to treat both lower extremity pain and deformity that is not always available with current techniques. Level of Evidence: Level IV, retrospective case series.