Internet-based science learning has been advocated by many science educators for more than a decade. This review examines relevant research on this topic. Sixty-five papers are included in the review. The review consists of the following two major categories: (1) the role of demographics and learners' characteristics in Internet-based science learning, such as demographic background, prior knowledge, and self-efficacy; and (2) the learning outcomes derived from Internet-based science learning, such as attitude, motivation, conceptual understanding, and conceptual change. Some important conclusions are drawn from the review. For example, Internet-based science learning is equally favorable, or in some cases more so, to learning for female students compared to male students. The learner's control is essential for enhancing students' attitudes and motivation toward learning in Internet-based science learning environments. Nevertheless, appropriate guidance from teachers, moderators, or the Internet-based learning environment itself is still quite crucial in Internet-based science learning. Recommendations for future research related to the effects of Internet-based science learning on students' metacognitive reflections, epistemological development, and worldviews are suggested. (Contains 2 tables.)