Chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players is a rare condition and a difficult problem to treat. Eight high school or college student baseball players with onset of symptoms in their adolescent ages were collected in this series. Their mean age at surgical intervention was 17.8 ± 1.99 years. The fracture was operated on with muscle splitting, ulnar nerve-sparing technique. Suture anchors were employed to fix the avulsed fragment. Visual analog scale, Mayo elbow performance score, and Conway scale were used for objective patient evaluation. The patients were followed up for 30.8 ± 10.2 months. Six patients have achieved solid bony union, and 2 had partial union. All patients showed no medial space widening on followed-up stress films. Visual Analogue Scale score improved from 9 to 0. The Mayo elbow performance score improved from 60 ± 10 to 85 ± 15 points pre- and post-operatively. The Conway scale had 3 excellent, 3 good, and 2 fair results. The average return to pitching occurred 7 months post-operatively at a rate of 75%. The present results indicate that open reduction and fixation with suture anchors is an effective treatment method for chronic ulnar collateral ligament humeral origin avulsion fracture in young baseball players.