Objective: The present study aims to explore the relative effectiveness of two group-based cognitive rehabilitation programs for reducing fatigue in pediatric acquired brain injury (pABI). Method: This is an exploratory study of secondary endpoints in a blinded, parallel-randomized controlled trial with children and adolescents (ages 10–17 years) with pABI and reported executive dysfunction. It investigates the effectiveness of a metacognitive program (pediatric goal management training, n = 36) compared to a psychoeducational program (pediatric brain health workshop, n = 37) for reducing fatigue (Pediatric Quality of Life Inventory, Multidimensional Fatigue Scale), 8 weeks and 6 months postintervention. Results: Seventy-three participants completed the allocated interventions, and 71 attended the 6-month follow-up. The results showed a significant decrease in parent-reported fatigue for both interventions from baseline to the 6-month follow-up. Forty percent of the total sample had a reliable change. There was no significant difference between the intervention groups, but a tendency in favor of the psychoeducational approach. Only subscales cognitive and sleep/rest fatigue showed significant reductions. In regression analyses, several factors predicted fatigue at 6 months follow-up, but only better global outcome and executive attention predicted a decrease in fatigue symptoms after 6 months. Conclusions: Group-based cognitive rehabilitation in the chronic phase of pABI, including education of parents and teachers, may be helpful in reducing fatigue. Global outcome and executive attention at baseline predicted fatigue improvement. Developmental factors are important to consider when tailoring pediatric interventions, as well as modifiable factors associated with fatigue. (PsycInfo Database Record (c) 2022 APA, all rights reserved)