Focusing on “collaborative learning” in Collaborative Online International Learning (COIL), the purpose of this paper is to review COIL in terms of pedagogical and theoretical background of social constructivism to examine and enhance COIL practices critically. Social constructivism is one of the ideologies that brought a shift in learning theory that started cooperative and collaborative learning. Underlying theoretical perspectives of Saussure, Maruyama, Vygotsky, and Bruner were considered. Also, various examples of COIL practices were critically analyzed. To assure the quality of learning in terms of collaborative learning, following unique qualities of COIL have been examined and proposed: nature of its framework and peer group, pedagogical setup, quality of interactions, and new contextual backgrounds.