Interdisciplinary collaborations between different academic disciplines can create knowledge and solutions to challenges that are beyond the scope of what a single discipline can achieve. However, little is known about how interdisciplinary teams of faculty and graduate students function as a whole and the processes that guide them as they work on collaborative tasks. Using Activity Theory, this qualitative study analyzed team meeting transcripts to examine interdisciplinary team interactions involving Science/Engineering and Science Education graduate students and faculty members as they co-developed laboratory activities for a grant-funded project. Several factors contributed to the team's success: shared goals (Object), environment (Community), and clear Division of Labor. Differences (contradictions) were found in the Tools, Rules, and Division of Labor; the PI and Science/Engineering graduate students tended to focus on the needed lab materials, and the Science Education members focused more on educational standards and teachers' ideas in the lab development (Tools). The PI and Science Education members set and enforced the team meeting agendas and deadlines (Rules). The Science/Engineering grad students focused on practical considerations to ensure the labs could successfully be implemented in a class setting (Rules) and were assigned the most tasks to complete (Division of Labor). The findings provide insight into the nature of interdisciplinary team dynamics between a Science/Engineering and Education grant team. The findings also suggest the importance of shared goals (Object), community development (Rules: Team Building), and the potential of capitalizing on different strengths and knowledge (contradictions) in an interdisciplinary team.