Lateral humeral condyle (LHC) fractures are frequent elbow injuries in children, and if neglected or inadequately managed, they can lead to complications such as cubitus valgus deformity, ulnar nerve issues, and instability of the elbow joint. This case report presents a 20-year-old male with bilateral neglected LHC nonunion, leading to severe cubitus valgus deformity (45° on the left, 41° on the right) and ulnar neuropathy. The patient underwent a combination of 35° closed wedge osteotomy and anterior transposition of the ulnar nerve (ATUN) using a posterior approach. Fixation was achieved with locking plates. Postoperatively, significant improvement in ulnar nerve function, full elbow motion, and satisfactory cosmetic results were observed. Complete osteotomy healing occurred at nine months, with preparations for contralateral surgery underway. The presence of fractures in both elbows with identical deformities makes this case unique in the literature. This case highlights the efficacy of combining closed wedge osteotomy with ATUN in a single procedure, offering a practical, less complex solution for neglected LHC nonunion with favorable outcomes in deformity correction and nerve function restoration.