Considerable research indicates that sleep disturbances and insomnia are more common and severe among individuals following a traumatic brain injury (TBI). It remains unclear, however, how the experience of multiple TBIs affect sleep disturbances and insomnia. The current study investigated the incidence and severity of insomnia and sleep complaints among active-duty military personnel who have sustained multiple TBIs. Upon intake at a military TBI clinic located in Iraq, 150 male military patients completed standardized self-report measures and clinical interviews. Patients were categorized into three groups according to history of TBI: zero TBIs (n = 18), single TBI (n = 54), multiple TBIs (n = 78). Rates of clinical insomnia significantly increased across TBI groups (P < 0.001):- 5.6% for no TBIs, 20.4% for single TBI, and 50.0% for multiple TBIs. Insomnia severity significantly increased across TBI groups even when controlling for depression, posttraumatic stress disorder, and concussion symptom severity (B = 1.134, standard error = 0.577, P = 0.049). Multiple TBIs are associated with increased risk for and severity of sleep disturbance among male military personnel.