Reducing errors within a healthcare setting remains high on the patient safety research agenda. More consistent performance has been sought by increased development of standardised operating procedures, but they are not always adhered to in practice. Previous studies have identified that a difference exists between the way a task is imagined to be completed, based on standardised protocols and procedures, and how the task is actually completed in reality. This study explores one area of healthcare, community pharmacy, and more specifically the task of dispensing medicines from prescriptions, to identify the gap between how dispensing is imagined to be completed through standardised operating procedures, and how it is actually completed in practice, by using Hierarchical Task Analysis as a framework. Document analysis of standardised operating procedures in 3 community pharmacies was used to produce 3 task analyses, which were compared with 3 task analyses produced from data collected through non-participant observations of the same 3 community pharmacies. Deviations between the two forms of task analyses were presented to community pharmacists in focus group discussions and it was found staff may deviate from standardised protocols because of various reasons, including: efficiency; availability of resources; thoroughness; and delegating safeguards. Potential implications for the work system include the benefit of greater collaboration between procedure writers and frontline workers, and the introduction of more flexible procedures, that allow the risks of any adaptions to be clearly realised. Further work must establish whether pharmacists recognise the safety implications of these gaps between work as imagined, and work as done, and initiatives should be established to ensure patient safety is not compromised due to these differences.