Study Design. Retrospective review. Objective. To assess the relationship between age and complications, and report age-stratified complication rates for the surgical treatment of adult scoliosis. Summary of Background Data. Literature examining age and complication rates for adult scoliosis surgery is conflicting. The Scoliosis Research Society (SRS) morbidity and mortality (M&M) database contains a large series of adult scoliosis patients that can be utilized to investigate this relationship. Methods. The SRS M&M database was queried from 2004 to 2007 to identify all cases of adult scoliosis. Data pertaining to patient age, complications, scoliosis, and surgery type were extracted from the database. Age-based analyses of clinical parameters were conducted using age as both a stratified categorical variable and as a continuous variable. Results. In our cohort of 5470 adult scoliosis patients, the overall complication rate was 13.5% and there was a 0.3% mortality rate. Patients who experienced complications were significantly older than those without complications (55.9±16.5 yrs vs. 51.2±18.7 yrs, P<0.001). When complications were stratified according to decade of age, there was also a statistically significant trend of increasing complication rates with each decade of life (P<0.001). Dural tears were the most common complication in patients over 50 years, whereas implant-related complications were the most common in patients less than 50 years. Conclusion. There was a clear association between increasing age and higher rates of major short-term complications, a factor that ought to be taken into account during treatment decision making and patient counseling.