Acute lung injury (ALI) associated with systemic inflammatory response syndrome (SIRS) is a systemic complication following subarachnoid hemorrhage (SAH), but the incidence and influence on prognosis are unclear. The incidences of SIRS and ALI were surveyed in a prospective multicenter study of 96 patients admitted for SAH between December 2004 and June 2007. Hunt and Hess grade and Glasgow Outcome Scale score were also investigated. Forty-eight patients were diagnosed with SIRS, and 26 developed ALI within 4 weeks of admission. Nineteen of the 26 patients with ALI were complicated by SIRS, and 7 developed only ALI. Thirteen of the 19 patients complicated by SIRS and ALI died, and this mortality was higher than for patients with only SIRS (3/29) and only ALI (1/7). Multivariate analysis of the development of SIRS and/or ALI and Hunt and Hess grade as risk factors associated with aggravation of the outcome showed that complication with SIRS and ALI had the highest risk. Half of the patients admitted for SAH developed SIRS, and more than 25% developed ALI. The prognosis for patients complicated by SIRS and ALI was poor, which indicates that prevention and active treatment of these two pathologies are important.