Ulnar collateral ligament (UCL) has the main function to be stress-resistant to elbow valgus overload. Multilayer tears require a reconstruction with a tendon graft. In this study, we report the clinical, radiographic, and ultrasound outcomes after tendon graft reconstruction for symptomatic UCL insufficiency. Among twenty-six subjects underwent elbow UCL reconstruction from 2006 to 2012, fifteen were available to be evaluated at a mean follow-up of 36months. Preoperative assessment included clinical examination and MRI. The outcome measures were the Mayo Elbow Performance Score (MEPS); the Oxford Elbow Score (OES); the Disabilities of the Arm, Shoulder, and Hand (DASH); and the Conway-Jobe Scale. Overall population was postoperatively investigated with X-ray and ultrasound (US). Reconstruction was performed with autograft (palmaris longus) in five cases and allograft (semitendinosus) in ten cases using the figure-of-eight configuration (five cases), the docking technique (eight cases), or a fixation with screws (two cases). We found a significant improvement in postoperative MEPS, OES, and DASH scores (p<0.01). One case was unsatisfied and required an additional procedure of ulnar nerve transposition 12months after the reconstruction. X-ray showed calcifications along the graft in ten cases. At US examination, all the grafts assessed appeared anatomically intact without structural changes, and the dynamic examination showed a slight medial laxity with the valgus stress maneuver without pain or other sign of medial instability. This study confirms the efficacy of the graft reconstruction for chronic UCL insufficiency and introduces fresh insight on the role of musculoskeletal ultrasound to evaluate the reconstructed UCL.