Pediatric posttraumatic stress disorder (PTSD) is a debilitating condition that is associated with significant functional impairment, diagnostic complexity, and limited evidence-based treatment options. Among its core features, trauma-related sleep disturbances-particularly nightmares-are highly prevalent, profoundly impairing, and contribute to the chronicity and severity of the disorder. Prazosin, a selective alpha-adrenergic antagonist, has demonstrated efficacy in adults for reducing nightmares and improving sleep, but pediatric data remain limited. This case report describes an adolescent male patient with chronic PTSD who achieved full symptomatic remission and functional recovery with prazosin monotherapy. The patient had previously failed to respond to multiple psychotropic classes, including antidepressants, mood stabilizers, and antipsychotics. After initiating prazosin and titrating to 3 mg nightly, he experienced rapid and sustained resolution of nightmares, improvement in sleep quality, and overall reduction of PTSD symptomatology. His UCLA Child/Adolescent PTSD Reaction Index scores declined from 61 to 11 over 20 weeks. This case is contextualized within a narrative review of the pediatric prazosin literature, and highlights pharmacologic rationale, safety considerations, and clinical utility. The findings underscore the central role of sleep disturbances as a pivotal treatment target in pediatric PTSD and support further research into prazosin's therapeutic potential in this population.