Background: the increasing demand on hospitalisation, either due to elective activity from the waiting lists or due to emergency admissions coming from the Emergency Department (ED), requires looking for strategies that lead to effective bed management. The aim of this study was to evaluate the effectiveness of a surgery admission unit for major elective surgery patients who were admitted for same-day surgery. Methods: we included all patients admitted for elective surgery in a university tertiary hospital between the 1st of September and the 31st of December 2006, as well as those admitted during the same period of 2008, after the introduction of the Surgery Admission Unit. The main outcome parameters were global length of stay, pre-surgery length of stay, proportion of patients admitted the same day of the surgery and number of cancellations. Differences between the two periods were evaluated by the T-test and Chi-square test. Significance at P < 0.05 was assumed throughout. Results: we included 6,053 patients, 3,003 during 2006 and 3,050 patients during 2008. Global length of stay was 6.2 days (IC 95%:6.4-6) in 2006 and 5.5 days (IC 95%:5.8-5.2) in 2008 (p < 0.005). Pre-surgery length of stay was reduced from 0.46 days (IC 95%:0.44-0.48) in 2006 to 0.29 days (IC 95%:0.27-0.31) in 2008 (p < 0.005). The proportion of patients admitted for same-day surgery was 67% (IC 95%:69%-65%) in 2006 and 76% (IC 95%:78%-74%) in 2008 (p < 0.005). The number of cancelled interventions due to insufficient preparation was 31 patients in 2006 and 7 patients in 2008. Conclusions: the implementation of a Surgery Admission Unit for patients undergoing major elective surgery has proved to be an effective strategy for improving bed management. It has enabled an improvement in the proportion of patients admitted on the same day as surgery and a shorter length of stay.