ABSTRACT The increasing need and appreciation for functional bilingualism has led to the rapid and widespread development of second language immersion programs throughout Canada. To date, research results indicate that programs in which children receive all their instruction during the primary grades in a second language are more successful than traditional approaches to second language instruction (e.g. FLESJ. In addition, evaluation of the overall development of children who are participating in such programs reveals no significant disadvantages, although there does appear to be a brief, temporary lag in the development of some aspects of native language functioning. Despite the general success of such programs, which are now beginning to gain wider interest in the U.S., there is a clear need for further research including such considerations as the broad range impact on overall development, the variety of individual differences among participating children, evaluation of alternative pedagogical techniques, and a more thorough evaluation of resulting second language skills.