This article presents the finding of an interim evaluation survey commissioned by the Education Bureau of Hong Kong on the effectiveness of the curriculum reform initiated in 2001. Drawing upon change theories for analysis of the study, the article examines the perceptions of both principals and teachers on the effectiveness of short-term curriculum development in schools from 2001 to 2006 through self-administered questionnaire survey as well as focus group interviews. The quantitative survey shows that evaluations from principals were more positive than those of frontline teachers in many aspects of the reform. Data collected from focus group interviews help explain the discrepancy in attitudes of these two stakeholder groups towards the reform. Insufficient knowledge, lack of support and consensus, and top-down initiation of the reform are the reasons accounting for the different responses to the reform. Strengthening professional development programs and developing a culture of collegiality and collaboration are the strategies recommended to improve the implementation of the curriculum reform in the medium-term phase (2007-2011). (Contains 7 figures and 1 table.)