Background: U-osteotomy with Taylor Spatial Frame correction is a rarely reported treatment method particularly well-suited for severe rigid equinus deformity in adults. The purpose of this study was to evaluate the effectiveness and efficacy of deformity correction and clinical outcome using this technique. Methods: We present a retrospective review of 30 feet in 26 patients who received U-osteotomy with Taylor Spatial Frame. Radiologic outcomes were measured using the anterior tibiotalar angle (TTA) with conventional weightbearing radiographs. Functional assessments included American Orthopaedic Foot & Ankle Society (AOFAS) ankle and hindfoot scores and patient satisfaction using Likert scale. Results: The etiology included trauma (9), neglected or relapsed clubfoot (6), spina bifida (5), poliomyelitis (4), Charcot-Marie-Tooth disease (4), and iatrogenic (2). All patients had equinus deformity with TTA more than 140 degrees (median 157.5, 141-177). There were varus deformity in 19 feet, limb length discrepancy in 6 legs, and genu procurvatum deformity in 2 legs. The duration of gradual correction was 53.6±13.5 days (33-73 days), and the external fixation time was 147.8±25.2 days (98-203 days). At last follow-up, TTA in all patients improved significantly ( P < .001) to 113.5 degrees (111.8-116.0). All patients had plantigrade feet, except for 2 cases of residual mild equinovarus deformity, 2 cases of residual mild hindfoot varus deformity, 1 case of moderate hindfoot varus recurrence. The AOFAS scores significantly improved ( P < .001) from 51.0 points (29.0-66.0) to 76.0 points (69.5-88.0). Eighteen patients were very satisfied, 6 patients were somewhat satisfied, and 2 patients were somewhat dissatisfied. Conclusion: Using minimally invasive U-osteotomy with Taylor Spatial Frame to gradually correct the adult severe rigid equinus deformity proved to be an effective and relatively safe method associated with high patient satisfaction rates. Level of Evidence: Level IV, case series.