The aim of this study was to retrospectively assess and compare the functional outcomes and complications following anterolateral versus posterior surgical approaches for the treatment of mid-shaft fractures of the humerus. Material/Methods: This study included 107 patients treated for mid-shaft fractures between May 2015 and July 2018. Demographic and surgical data were collected for each patient. During follow-up visits, radiographs were acquired and evaluated. The clinical outcomes of the involved joints were assessed by the Constant scoring system, range of motion (ROM), and the Mayo Elbow Performance Scoring system at the 12-month follow-up. Results: The posterior approach was performed in 57 patients with type A fractures (group I, n=28) and type B or C fractures (group III, n=29). The anterolateral approach was performed in 50 patients with type A fractures (group II, n=32) and type B or C fractures (group IV, n=18). There were no significant differences between group I and group II nor between group III and group IV with respect to patient demographic data, surgical data, Constant score, ROM, or Mayo Elbow Performance score. A significant difference in the total complication rate was observed between group I and II. Conclusions: The anterolateral approach showed an advantage over the posterior approach for treating simple humeral midshaft fractures. However, this advantage was not observed in treating comminuted fractures.