Lesson study professional development, LSPD, is a technique during which teachers work collaboratively to create, implement, revise, and reflect on a specific lesson (Fernandez, 2002). This research proposed that using LSPD on integrating technology into teaching would provide teachers a collaborative and safe way to explore technology use in their classrooms. Technology adoption is not a single occurrence, but a process that takes time (Fullan, 2007; Roger, 2003). Unlike traditional forms of training, LSPD provides sustained support and a way to test technologies in low stakes situations through collaboration and observation. Both of these aspects, experimentation and observation, are important in the adoption of technology (Rogers, 2003). This study was aimed at understanding how teachers in a technology-infused LSPD change their beliefs and practices over time. Research questions included the following: a) how would teachers in a technology-infused LSPD develop their attitudes toward technology and in their technological pedagogical content knowledge (TPACK)?, b) how would teachers in a technology-infused LSPD change their lesson planning and teaching behaviors?, and c) would certain features of the group play a role in the teachers’ development? To address these questions, the study took qualitative approach to understanding teachers’ experiences during the lesson study process. Using interview transcripts, lesson plans, group meeting transcripts, and field notes, group cases were compiled to examine the experiences of the groups. Although three groups of teachers were followed during the semester, only one team was able to plan, teach, and re-teach a lesson. The LSPD process was disrupted by several factors independent of the lesson study model and more related to mandated testing and its results at the individual school level. The focus of the study shifted to describing the factors that contributed to and interfered with the carefully planned professional development model. The findings in this study can help us better understand the impact and intricacies of LSPD. / text