The CT scans of 400 consecutive children evaluated with CT following blunt abdominal trauma were evaluated to determine the frequency of periportal low-attenuation zones, assess patterns of associated intraabdominal injury, and examine clinical outcome. Periportal low-attenuation zones were noted in 60 children (15%). The presence of these zones was associated with a significantly higher incidence of intraabdominal injury (60% versus 11%, p = 0.0001). Injuries most frequently associated with zones of periportal low-attenuation included hepatic (n = 23, 38%), and adrenal (n = 14, 23%). Children who had periportal low-attenuation zones tended to be more physiologically unstable as evidenced by a lower Trauma Score (diffuse, 11.9; focal, 13.4) than children without the zones (15.1, p = 0.0001). The presence of these zones was also associated with a significantly higher mortality rate (13% versus 1%, p = 0.0001). Ten children who had periportal low-attenuation zones and no hepatic injury on CT had a normal appearing liver on gross inspection at surgery or autopsy. In conclusion, periportal low-attenuation zones are common in children who have hepatic injury. These zones may be seen in conjunction with non-hepatic visceral injury or in the absence of intraabdominal injury. The presence of zones of periportal low-attenuation is associated with a higher index of physiologic instability, and higher mortality.