Background: In this retrospective study we analyzed a consecutive series of patients affected by isolated radial head Mason III fractures and treated with an on-table reconstruction technique combined with miniplate internal fixation or prosthesis.Methods: This study included 42 patients affected by isolated radial head Mason III fractures and treated between Jan 2012 and Jan 2019. Twenty-four patients (average age 45.6 years) were treated with an on-table reconstruction technique combined with miniplate internal fixation. The remaining 18 (average age 44.5 years) were treated with prosthesis. From a clinical point of view, we evaluated the patients according to the Broberg–Morrey scoring system and the (disabilities of the arm, shoulder, and hand) DASH questionnaire for parameters.Results: We found similar results in both the groups according to Broberg–Morrey score system and the DASH questionnaire at the last follow-up. The scores of the prosthesis group were better than those of the internal fixation group at the 1st, 3rd, and 6th month follow-up post-operation.Conclusion: Both the on-table reconstruction technique combined with the miniplate internal fixation and prosthesis can be effective in treating patients with isolated Mason III radial head fractures. There was no difference in elbow function between the two groups at the last follow-up; however, a prosthesis favors early functional recovery of the elbow.