Background: Crush injuries are associated with extensive soft tissue damage leading to a high risk of complications. Differences between pediatric and adult patients remain poorly studied. This study aimed to compare outcomes after crush injury in pediatric and adult patients and to identify predictors of viability-related complications (VRCs). It was hypothesized that children sustained fewer complications than adults following extremity crush injuries. Methods: A retrospective comparative cohort study was conducted at a level-1 trauma center. Pediatric patients (<16 years) treated between 2017 and 2024 and adult patients (≥16 years) treated between 2019 and 2023 were included. Patients with crush injury not involving extremities were excluded. VRCs were defined as (secondary) tissue necrosis, infection (related to impaired tissue viability), or both. The primary outcome was incidence of VRC in pediatric patients compared to adult patients. Group comparisons were performed using Chi-square testing. Logistic regression analyses were performed to identify independent predictors of VRC. Results: A total of 116 patients were included, of whom 36 were pediatric patients and 80 were adult patients. VRC occurred in 13.9% of children, compared to 56.3% of adults (p < 0.001). Isolated necrosis did not occur in pediatric patients within the cohort. Multivariable logistic regression identified age, degloving injury and open fracture as independent predictors of VRC. ISS and fasciotomy were not associated with VRC. The risk of VRC increased progressively with age, with a 2.5% increase in odds per additional year of age. Conclusions: Pediatric patients had a substantially lower incidence of viability-related complications after crush injury than adults. The results of this study suggest the presence of age-related differences in tissue viability after trauma, which may warrant corresponding surgical approaches. An increased understanding of age-related differences will contribute to more individualized treatment strategies in complex traumatic injury.