This study aimed to examine aspects of the introduction, in the state of Victoria, Australia, of an externally mandated; system wide.; curriculum change, the Victorian Certificate of Education ( VCE). More specifically, the emphasis was on changes to the study of mathematics. Three questions were investigated. How did the teachers respond to this change ? What was the influence of the extensive public debate that arose over the VCE? What were the factors which helped or hindered the implementation of this change? The investigation was a longitudinal study taking place over the four year period from 1989 to 1992. The focus was on the changes to mathematics, seen through the lens of a group of teachers in a school charged with implementing the change through a series of phases. Qualitative methodological techniques were used to gather data. These included a case study approach collecting data from the school where the author, as a researcher, took the position of a participant observer. In addition a content analysis of published articles in the popular press and official publications was undertaken. The study found that the VCE was successfully implemented due to its adoption by teachers and their willingness to work hard to ensure its success which arose from a commitment to their students. Also that two of the underlying tenets of the VCE remained intact, despite other changes. These tenets were that the VCE remained a single certificate and that a breadth of subject choice for students was available. Factors which hindered the successful implementation were the lack of professional development, funding, resources, support and consultation, while at the same time teachers were expected to carry a significantly increased workload. The public debate over the introduction of the VCE, set in the context of an impending election, was a major influence in causing changes to some aspects of the VCE. Changes which occurred in consultation with teachers tended to aid implementation while other imposed changes tended to hinder or slow implementation. An unpredicted outcome of the introduction of the VCE was that the work requirement approach to teaching was accepted as a valuable process and was incorporated into lower levels in schools.