Introduction Congenital scoliosis with unilateral unsegmented bar has remained a surgical challenge. If it is treated with a traditional release of the convex side and an apical wedge osteotomy, there is a risk of bony bridge fracture on the concave side and spine translation during correction maneuvers, which may then result in spinal cord injuries. The authors developed a technique that consists of a concave-side costovertebral joint release followed by both-ends wedge osteotomy via a posterior-only approach. In this article, we describe the technique in detail, and present the results of ten patients treated with this technique. Methods A total of ten patients with congenital scoliosis with unilateral unsegmented bar, who had undergone a concave-side costovertebral joint release followed by both-end wedge osteotomy via a posterior-only approach were followed up for a mean of 34 months (range 26-48 months). The radiographic parameters and clinical records were all reviewed and analyzed. Results Body height increased by a mean of 7.3 cm (range 6.0-9.0 cm). The preoperative coronal Cobb angle was 102°(range 83°-139°) with a mean flexibility of 14%. At the most recent follow-up visit, the mean Cobb angle was 35°(range 12°-53°) and the mean correction rate was 66%. The coronal imbalance improved from 3.4 cm (range 0.8-6.3 cm) preoperatively to 1.1 cm (range 0.6-1.8 cm) postoperatively, a 67% correction. There were no definite pseudarthroses, no implant failure, and no obvious loss of correction in the follow-up period. Complications included one patient with hemopneumothorax and another patient with incomplete paralysis of the left lower extremity caused by a pedicle screw violating the spinal canal at the T5 level. The screw was removed 4 h after the initial operation, and the patient fully recovered after 3 months. Conclusion We have had good results with our technique of concave-side costovertebral joint release and both-end wedge osteotomy. It has the advantage of remnant anulus fibrosus, the ligamentum flavum, and the facet joints on the concave side serving both as a hinge and to minimize translation of the spine ends. It can provide excellent threedimensional curve correction for patients with severe rigid congenital scoliosis with unilateral unsegmented bar.