Service quality is commonly though to comprise five generic dimensions - responsiveness, assurance, tangibles, empathy and reliability. These dimensions form the basis for service measurement tools such as SERVQUAL. Research in this area, using tools such as SERVQUAL has predominantly focused on customer perceptions of quality. However, another approach used by many organisations is to send trained raters into the service environment, posing as customers to evaluate service levels. This approach is often called "mystery shopping" and is very commonly used in both private and public sector organisations. This study examines whether the accepted service quality dimensions derived from customer perceptions studies are reflected in service quality evaluations using mystery shopping. It finds that the dimensions that emerge from mystery shopping data resemble SERVQUAL dimensions. Furthermore, a replication found that those dimensions are reasonably stable over time. The findings suggest that data from mystery shopping surveys can exhibit convergent validity.