Objective: The relationship between sleep disturbance and cognition remains ill defined across the course of concussion recovery. Our aim was to investigate acute post-concussive sleep disturbance as a potential indicator for delayed cognitive recovery. We hypothesized that greater reported sleep disturbance at patient intake would significantly relate to poorer cognition (verbal and visual memory, processing speed and reaction time) at the final appointment. Method: A total of 18 outpatient, non sport-related post-concussive patients (M = 35.78 years, SD = 14.49, 55.60% female) in the acute phase of injury (<4 months) were administered ImPACT cognitive testing, ImPACT symptom checklist and a 10-item Sleep Disturbance and Impairment Questionnaire developed for concussion patients. Patients were administered all sleep and cognitive measures at intake and exit (typically 2-6 weeks later). Results: Bivariate correlations were conducted between sleep disturbance scores at intake and ImPACT cognitive scores at exit. There was no association between ImPACT verbal or visual memory scores and any sleep disturbance indices. Slower processing speed was negatively related to greater reported “trouble falling asleep” (r = −.91, p < .001), “sleeping less than usual” (r = −.78, p < .05) and global sleep disturbance (r = −.83, p < .01). Slower reaction time was positively correlated to greater “trouble falling asleep” (r = .87, p < .001), “sleeping less than usual” (r = .77, p < .05) and global sleep disturbance (r = .79, p < .01). Hypersomnia and daytime sleepiness symptoms were unrelated to any cognitive indices. Conclusion: Findings underscore sleep disturbance, particularly insomnia-related symptoms, as an indicator for slowed cognitive recovery related to processing speed and reaction time. Although our study included gross measures of sleep disturbance, future research should aim to incorporate insomnia-specific sleep measures.