Despite the prominence of neuropsychological deficits in memory, attention and learning in adults exposed to trauma and those who develop posttraumatic stress disorder (PTSD), few studies have explored these cognitive deficits in adolescents. This study aimed to assess the impact of PTSD on various neurocognitive functions in South African adolescents. In a case-control study, 40 traumatized adolescents (20 with PTSD and 20 without) were evaluated for the presence of PTSD and were then referred for neuropsychological evaluation using a standardized neuropsychological test battery. The presence of PTSD itself, rather than trauma exposure, was associated with cognitive deficiencies in attention, visual memory and nonverbal concept formation. This study highlights the impact of PTSD itself-and particularly current symptoms-on the cognitive development of adolescents. As this effect appears to be stronger than the impact of trauma alone, more studies on the long-term consequences of PTSD on youth cognitive development are crucial.