An integrated bilingual science instruction model is described. Intended primarily for Spanish-speaking children in the Southwest, it specifies how the dominant language skills and the second language might be synchronized and be mutually supportive with science learning in a way relevant to the Latino culture. For purposes of discussion and clarification, the integrative model is contrasted with three hypothetical models: the transfer, the balanced bilingual, and the ESL models. It is argued that a problem-solving approach to science instruction with the proper hands-on activities could improve the bilingual/bicultural program by: (1) focusing more on cognitive operations of science; (2) involving the children in actual problem-solving thought processes; and (3) improving skills in both languages. More specifically, the model spells out how skills in both languages can be used in a basically immersion approach, that is, an approach which uses science-oriented materials to teach the second language. Further, the model is directed toward teaching both English and Spanish as second languages through science instruction. Because there is a lack of bilingual science materials appropriate for Southwest Spanish speakers, it is suggested that teachers develop materials from hands-on materials written in English for teacher use. Suggestions are made for this procedure as well as for creation of materials by the teacher. (Author/AMH)