Thirty studies published between 1977 and 2001 that focus on outcome following unruptured intracranial aneurysm (UIA) treatment are reviewed. Although findings from these studies suggest outcome from UIA treatment is reasonably good (between 5% and 25% morbidity and between 0–7% mortality), many of the complex issues associated with the treatment of UIAs remain controversial. Most of the studies reviewed address outcome in terms of mortality and neurological morbidity. Very few studies exist which include measures of outcome such as cognitive status, psychosocial functioning and quality of life. Given that patients facing treatment tend to be healthy middle-aged adults with many years of active working and social life ahead of them, it is important to take into account the long-term consequences of either harboring an UIA, or having it treated. The small number of studies that include cognitive, psychosocial and quality of life outcomes are reviewed in some detail and suggestions made for improving future UIA outcome research. (JINS, 2004, 10, 114–134.)