Objective: The literature suggests that mild traumatic brain injury (mTBI) patients may have the highest incidence of failed symptom validity testing versus other neurological populations. Likewise, mTBI populations present with the greatest sleep disturbance compared to more severe forms of TBI. Although higher incidence of failed symptom validity testing and increased sleep disturbance has been independently documented in mTBI patients, the specific relationship between sleep disturbance/quality and symptom validity performance has yet to be evaluated in this population. Method: Sixteen mTBI patients (62.5% male; M = 43.56 years, SD = 11.31) were administered the Rey-15 Item Test, Test of Memory Malingering (TOMM), the California Verbal Learning Test (CVLT-II) Forced Choice, the Millon Clinical Multiaxial Inventory (MCMI-III), and completed the Pittsburgh Sleep Quality Index (PSQI), which includes the following sleep indices: sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, sleeping medications, and daytime dysfunction. Results: Results of a bivariate correlation indicate a moderate to strong positive correlation between average total sleep hours and the Rey-15 combination (reproduction + recognition) score (r = .62, p = .04). Additionally, poor sleep efficiency (total sleep time/time spent in bed) strongly negatively correlated to the Rey-combination score (r = −.77, p = .01). Interestingly, sleep indices were unrelated to the TOMM trials one and two, CVLT-II Forced Choice and the MCMI validity scales. Conclusion(s): These findings highlight the potential role of sleep in symptom validity performance, particularly in validity testing that requires item reproduction versus solely item recognition.