Aretrospective hospital-based case-control study was performed with the aim to evaluate the association between exposure to anesthesia and Alzheimer's disease (AD). A total of 115 AD patients, 230 Parkinson's disease (PD) patients and 230 patients with non-degenerative neurological disease were studied. Each AD case was matched for sex, age (+/-3 years) and geographic area of residence with four controls (2 PD patients and 2 with other neurological disease). Information about exposure to general anesthesia and other variables was gathered through hospital records. No associations were found between the risk of AD and the exposure to anesthesia in the 1 and 5 years preceding disease onset, nor between the risk of AD and the number of surgical operations. A significant difference was observed between the mean age of AD patients and controls undergoing surgical procedures. The present study reveals a lack of association between exposure to general anesthesia and AD. Prospective epidemiological studies are needed in order to investigate levels of exposure to anesthesia, as well as any possible relationships between anesthetic exposure and genetic factors (e. g. APOEepsilon4 genotype).