With the implementation of Project 2000 in the UK the traditional student nurse workforce has largely been replaced by health care assistants (HCAs). This study was carried out in Hong Kong at a time when university-based nurse education is gradually being introduced. Evaluation of a HCA pilot programme in an acute care hospital in Hong Kong provided the opportunity to examine the work of HCAs and hospital-based student nurses during the gradual introduction of university-based nurse education. The data used in this paper were drawn from a larger study evaluating the use of HCAs. The observational data collected at two phases after the introduction of HCAs were analysed using Kruskal-Wallis one way analysis of variance. No significant differences were found in the total amount of all types of activity performed by SNs and HCAs. However in the direct care type of work HCAs performed significantly more basic care and less technical activity than any level of student at phase 1 (P<0·001) and phase 2 (P<0·001). These differences in the work undertaken suggest that qualified staff do not perceive SNs and HCAs as equally unqualified. Thus the replacement of SNs with HCAs alone is likely to lead to a notable change in the role of qualified staff in terms of their direct and indirect care activities and in the amount of time spent delegating and supervising unqualified staff.