A needs analysis conducted as part of the foundation-based education (FBE) innovation on the island territory of Sint Maarten indicated the need for additional training of early primary teachers (PK-2) in mathematics and science education. Seven in-service workshops, designed around the Joyce-Showers' Training Model, were implemented over the course of an academic year. Participants included teachers from all five school types: Adventist, Catholic, Methodist, Christian non-denominational, and public schools. Pre- and post-measures were collected via tests given the teachers. Results showed that teachers demonstrated real gains in all domains that were tested: mathematics content, science content, mathematics and science methods, and FBE methods. Additionally, the number of teachers reaching the minimum competency score increased dramatically. While differences in scores existed by school type on the diagnostic assessment, these differences were smaller on the post-treatment assessment measure. The study results show the use of the Joyce-Showers' Training Model for teacher development can work in a specific Caribbean context. Results also support the idea that systemic innovation is possible in Sint Maarten with careful planning and appropriately designed support. © Taylor & Francis Group.