This paper presents findings of a case study that examined Australian primary teachers' perceptions of school-based curriculum development (SBCD). The study was conducted at Blackpool Primary School, a Catholic school in Sydney, New South Wales, Australia. Data were derived from participant observation, a teacher questionnaire, interviews with all full-time teachers, and followup focus interviews with two of the teachers between August 1987 and June 1988. Findings indicate that despite the presence of support structures and a high level of teacher involvement in curriculum planning, several initiatives did not find expression in the classroom. Teachers did not see implementation as part of their participation in SBCD, nor did they relate SBCD to personal benefits. They also reported that they lacked time and sometimes made decisions based on what they believed was best for their students. It is recommended that the administration explore the link between curriculum planning and implementation with students in teacher-preparation programs. Four tables are included. (LMI)