The 2006 National Science Board called for new strategies and instructional materials for teachers to better serve English Learners' (EL) needs. Bilingual Collaborative Online Projects in science were created to assist ELs' construction of science knowledge, facilitate academic English acquisition, and improve science learning. Two bilingual Collaborative Online Project units in science are freely available on an instructional website: the Let's Help Our Environment and the What Your Body Needs units. These projects combine two constructivist approaches, Project-Based Learning and the Cognitive-Affective Theory of Learning with Media, for the teaching of science embedded in culturally and linguistically relevant instruction. This study hypothesizes that Collaborative Online Projects will assist ELs' construction of science knowledge and facilitate academic English. Results of a pre-/post-test design pilot study (N = 136) showed statistically significant differences for both tested science units. Teachers also reported that the Collaborative Online Projects were an effective method of online science instruction.