Indigenous science relates to both the science knowledge of long‐resident, usually oral culture peoples, as well as the science knowledge of all peoples who as participants in culture are affected by the worldview and relativist interests of their home communities. This article explores aspects of multicultural science and pedagogy and describes a rich and well‐documented branch of indigenous science known to biologists and ecologists as traditional ecological knowledge (TEK). Although TEK has been generally inaccessible, educators can now use a burgeoning science‐based TEK literature that documents numerous examples of time‐proven, ecologically relevant, and cost effective indigenous science. Disputes regarding the universality of the standard scientific account are of critical importance for science educators because the definition of science is a de facto “gatekeeping” device for determining what can be included in a school science curriculum and what cannot. When Western modern science (WMS) is defined as universal it does displace revelation‐based knowledge (i.e., creation science); however, it also displaces pragmatic local indigenous knowledge that does not conform with formal aspects of the “standard account.” Thus, in most science classrooms around the globe, Western modern science has been taught at the expense of indigenous knowledge. However, because WMS has been implicated in many of the world's ecological disasters, and because the traditional wisdom component of TEK is particularly rich in time‐tested approaches that foster sustainability and environmental integrity, it is possible that the universalist “gatekeeper” can be seen as increasingly problematic and even counter productive. This paper describes many examples from Canada and around the world of indigenous people's contributions to science, environmental understanding, and sustainability. The authors argue the view that Western or modern science is just one of many sciences that need to be addressed in the science classroom. We conclude by presenting instructional strategies that can help all science learners negotiate border crossings between Western modern science and indigenous science. © 2000 John Wiley & Sons, Inc. Sci Ed 85:6–34, 2001.