There has been a tremendous growth in day surgery units to meet the demand for cost-effective healthcare. As a result of increased outpatient use of these units, procedures for administrative and clinical management have been developed. The effectiveness of the use of these protocols, however, has not been tested. This article reports on a study that examined nurses’ compliance with a protocol for postprocedural vital signs measurement in a gastrointestinal day unit. The protocol’s effectiveness in detecting postprocedure complications and the resource implications of the protocol were examined. The rate and type of postprocedure complications detected are also reported.Analysis of the observation data suggests staff are undertaking observations according to the protocol for most patients. Some patients appear, however, to be having their observations done outside the time frame recommended by the protocol. It is possible that staff are exercising their clinical judgement and continuing observations on some patients, though this is speculation and requires further research. Findings from the study raise questions regarding whether postprocedure monitoring is resource efficient.