The objective of this study is to retrospectively assess the use of single-plate (SP) and double-plate (DP) fixation in the open reduction and internal fixation of comminuted clavicle fractures, focusing on fracture union and complications. We retrospectively evaluated comminuted diaphyseal clavicle fractures (Arbeitsgemeinschaft für Osteosynthesefragen type 15.B1-3) treated with open reduction and internal fixation and having a minimum 1-year follow-up. Two patient cohorts were identified: DP (utilizing a superiorly located clavicle-specific plate and an anteriorly located tubular plate) and SP (utilizing a superiorly located clavicle-specific plate). These groups were compared in terms of union time, peri-incisional numbness, implant irritation, return to work time, union rates, re-operation rates, Disabilities of Arm, Shoulder and Hand (DASH), and American Shoulder and Elbow Surgeons (ASES) scores. The study included 27 SP and 23 DP patients meeting the inclusion criteria. There was no significant difference between the 2 cohorts in terms of union time, peri-incisional numbness, implant irritation, return to work time, union rates, re-operation rates, DASH, and ASES scores at the end of the first year (P = .889, P = 1.00, P = .122, P = 1.00, P = 1.00, P = .493, P = .736, P = .762, P = .937 respectively). However, it was observed that the DP group showed a significantly earlier return to work time and better DASH scores at 3rd and 6th months, whereas the SP group exhibited significantly better ASES scores at 3rd and 6th months (P = .034, P = .016, P = .032, P = .036, P = .021, respectively). No significant difference was observed in terms of union and complications in acute clavicle fractures treated with SP and DP fixation. The DP group demonstrated an earlier return to work and superior early functional scores compared to the SP group. Our findings suggest that a secondary plate can be reliably used, particularly in situations where clavicle fracture fixation is insufficient or in cases of comminuted clavicle fractures.