Diabetes mellitus (DM) has been shown to be a risk factor for subarachnoid hemorrhage (SAH). However, the influence of this disease on outcome from SAH has not been adequately studied. We retrospectively reviewed 150 patients with SAH, including 22 with and 128 without DM. Our results indicate that pre-existing DM does not significantly influence outcome from SAH when examined in conjunction with other chronic diseases and epidemiological factors.