ABSTRACT   The purpose of this medical record research was to study 30 patients with chronic subdural hematoma on a neurosurgical clinic, mapping documented nutritional status, preoperative fasting and hydration and energy supply before surgery. In addition peroperative administration of fluid and vasoactive drugs, as well as postoperative complications and length of hospital stay were studied. The mean age of the patients was 71 years. Nutritional status was evaluated in 12 patients, out of these seven were judged to be at risk for under nutrition. Fifteen patients had surgery day 1 (total fasting time on average m 11 h), eleven had surgery day 2 (29 h), three had surgery day 3 (35 h). One patient had surgery day 4 (61 h). Fluid and energy administration during the preoperative fasting did not meet the basic requirements. The majority of the patients received vasoactive drugs and more than twice the normal requirement of fluids during anesthesia. Postoperative complications were documented in 11/30 records. There was a significant correlation between preoperative fasting hours and length of hospital stay, however there may not be a causal relationship.   The conclusion is that the fasting period is significantly longer than the guidelines recommend and the patients do not receive their preoperative fluid and energy requirements, which may lead to an increased number of postoperative complications and prolonged hospital stay. A goal of the treatment should be that the preoperative fasting time is kept as short as possible and that the basal fluid and energy requirements are met. An evidence based strategy for this purpose should be created.