Objective: Previous research suggests that neuropsychological outcome after pediatric concussion is determined by unmodifiable, preexisting factors. This study aimed to predict neuropsychological outcome after pediatric concussion by using a sufficiently large sample to explore a vast array of predictors. Method: A total of 311 children and adolescents (6–18 years old) with concussion were assessed in the emergency department to document acute symptomatology and to screen for cognitive functioning. At 4 and 12 weeks postinjury, they completed tests of intellectual functioning, attention/working memory, executive functions, verbal memory, processing speed, and fine motor abilities. Multiple hierarchical logistic and linear regressions were performed to assess the contribution of premorbid factors, acute symptoms, and acute cognitive screening (Standardized Assessment of Concussion–Child) to aspects of neuropsychological outcome: (a) cognitive inefficiency (defined using a modified Neuropsychological Impairment Rule; Beauchamp et al., 2015) and (b) neuropsychological performance (defined using principal component analysis). Results: Neuropsychological impairment was present in 10.3% and 4.5% of participants at 4 and 12 weeks postinjury, respectively. At 4 weeks postinjury, cognitive inefficiency was predicted by premorbid factors and acute cognitive screening, whereas at 12 weeks it was predicted by acute symptoms. Neuropsychological performance at 4 weeks was predicted by a combination of premorbid factors, acute symptoms, and acute cognitive screening, whereas as at 12 weeks, only acute cognitive screening predicted performance. Conclusions: Neuropsychological outcome after pediatric concussion is not attributable solely to preexisting problems but is instead associated with a combination of preexisting and injury-related variables. Acute cognitive screening appears to be particularly useful in predicting neuropsychological status after concussion.