Objective: To examine the relationship between noncredible effort, symptom severity, and amount of school days missed after a mild traumatic brain injury (mTBI). We hypothesized that children who failed symptom validity measures (SVMs) would report more post-concussion symptoms and miss more days of school than those who passed. Method: Participants were 32 patients (males = 12; females = 20) with protracted recovery following mTBI and were clinically referred for neuropsychological testing. Average age was 13.79(2.72). All patients met criteria for mTBI using the Acute Concussion Evaluation (ACE). Mean number of days since mTBI was 91(76), and mean percentage of days missed from school was 27%(.3). The Postconcussion Symptom Scale (PCSS) of the Sport Concussion Assessment Tool, Third Edition (SCAT-3) was used to assess post-concussion symptoms. Classification of effort status (i.e., pass vs fail) was determined using published cutoff scores on one of the following three SVM's: Nonverbal Medical Symptom Validity Test (NV-MSVT), Test of Memory Malingering (TOMM), and Rey 15-item test. Independent samples t-tests were used to examine between groups differences among children who passed and failed SVM's. Results: Patients who failed effort testing reported more post-concussion symptoms than those who passed t(30)= 1.88, p = .022. However, there was no significant between groups difference for percentage of school days missed t(20) = 1.05, p = .306. Conlcusion: Consistent with recent research, results suggest post-concussion symptom exaggeration in children who fail effort testing. However, contrary to our expectation, children who failed effort testing did not miss more days of school than those who passed.