Introduction: Ambulatory surgery is a standard of care for many surgical procedures due to cost-effectiveness and benefits to patients including the reduced risk of contracting hospital infection by reducing the hospital stay. However, late cancellations can be costly. We examined the utilisation of the surgical day ward in our institution over a four-year period. Methods: A retrospective study of surgical day ward records from September 2007 to September 2011 in one institution. Parameters investigated included the number of planned admissions. Reasons for cancellations were also collected. Results: A total of 17,461 procedures were intended as a day ward admission during the study interval. There were 3,539 procedures that were cancelled (20.3%). The prevalent proportion of cancellations (n = 1,367) (38.6%) were due to patients not showing up for their procedures (7.8% of planned admissions); 1,188 (33.6%) patients were cancelled by the admissions office due to bed shortages, accounting for 6.8 % of planned admissions and 650 (18.4%) of cases were due to last minute cancellations by patients, accounting for 3.7% of all planned admission. The remaining 334 (9.4%) of cases were cancelled on medical grounds including patients who were considered unfit for the intended procedure, or anti-coagulations not appropriately ceased prior to surgery, accounting for 1.9% of all planned admissions. Conclusion: The cancellation rate in this study was high, mainly due to failure of patients to attend or signal their intentions, inadequate bed capacity and bed closure strategies. The ring fencing and protection of day beds and a more active patient management interaction would have had the greatest impact on increased efficiency.