Scientific problems of the twenty-first century involve complex research questions that require an interdisciplinary approach. Educational research suggests that overall student achievement is greater in an interdisciplinary science curriculum than in a discipline-specific science curriculum. Regardless, the secondary school science curriculum in Ontario remains discipline-specific. The Ontario Ministry of Education (OME) released an 'Interdisciplinary Studies' curriculum in 2002; however, it appears to be sparsely implemented across Ontario. The objective of this study is to investigate what guidelines are provided by the OME to help Ontario secondary school science teachers (grades 11-12) design and implement interdisciplinary science courses. A document analysis methodology is used to gather data from selected OME curriculum documents. The results of this study found that interdisciplinary science courses are based on multiple models of interdisciplinarity; however, the guidelines provided for developing interdisciplinary curriculum, assessment, and teaching methods do not explicitly indicate which type of interdisciplinary model is applied, nor do the documents explicitly consider the degree of integration of concepts and skills from across disciplines/subject areas. Primarily, the results of this study may inform Ontario Ministry science curriculum writers, teachers and educators interested in interdisciplinary science curriculum elsewhere, about what aspects of the selected curriculum documents provide practical information for developing interdisciplinary science courses and components of the curriculum that may warrant potential revisions or additions during future curriculum drafting.