Collaborative teaching is a dynamic process in which educators are continuously engaged in restrategizing to fit their curricular goal. This article aims to describe how the use of collaborative teaching in a course on proposal writing benefited a group of graduate students studying teaching English as a foreign language. Throughout the study, two educators jointly planned the course and provided guidelines to the participants on how to choose a topic for research, develop it into a well-structured written proposal, present it to class, negotiate it with their classmates, and provide feedback to each other's presentations. They also collaboratively provided the students with critical feedback on each step of the above activities. Moreover, the assessment of the course was designed and implemented collaboratively, including assessment of the students' two oral presentations of their proposals, their final written proposals, and the survey of their opinion through a questionnaire. The results indicated the participants' improvement in terms of writing their proposals as compared to each of their oral presentations, their acknowledgment of collaborative teaching, and its impact on increasing their motivation as well as tendency for both collaborative and competitive learning.