This study aims to theoretically explore whether Massively Multiplayer Online Game (MMOG) is an effective collaborative learning environment, empirically examine the occurrence of knowledge creation in MMOG game-play, and conceptually advocate the research potential of MMOG game-based collaborative learning. Although a growing number of researchers have started to use MMOG as a new generation of educational platform, the study of the theoretical justification for the occurrence of collaborative learning behavior in MMOG are still under-researched. To bridge this gap, this study integrates MMOG and technology-based collaborative learning streams of research to theoretically explore whether MMOG is an effective learning platform based on Alavi’s three attributes of effective technology-mediated collaborative learning environment. In order to examine the occurrence of knowledge creation in the MMOG game-based collaborative learning, we propose definitions of explicit and tacit knowledge in MMOG. Then we conduct an exploratory study using a semi-structural interview approach to collect qualitative data, in order to support our stipulation of the occurrence of four modes of knowledge conversion in MMOG game-play based on the Nonaka’s dynamic theory of organization creation. According to our research findings, this paper advocates research potential of MMOG game-based collaborative learning in future research.