It is known that during a fall, a child would rather protect their dominant hand by using the non-dominant one, although the role of handedness in upper limb fractures has not been studied in-depth. We carried out a retrospective, cross-sectional cohort study, including pediatric patients who presented to the emergency room with a supracondylar humerus fracture following an injury by falling from the same height. In total, 245 patients were selected and grouped according to age. In the 1–3 years group, no statistical significance was found between hand dominance and the side of fracture (p = 0.7315). During preschool years (4–6 years old), the non-dominant hand is more often involved (p = 0.03, odds ratio: 3.5). In the 7–14 years group this trend was maintained and actually increased (p = 0.052, odds ratio: 3.8). We might conclude that children tend to protect their dominant hand by falling on their non-dominant one. The main objective of this study is to highlight a link between handedness and the side of the body where the hand fracture will be identified in the pediatric population, regarding supracondylar humerus fracture.