This paper reports the use of Google Docs in a master's degree program as an online tool for collaborative co-construction of knowledge and self-assessment. Participants included eighty graduate teachers in a master's degree. The study employed a mixed method approach. Among the tools applied were a questionnaire, focus group discussions, collaborative Google Docs, students' comments, class discussions and instructor assessments of the collaborative process. Results indicated positive experiences when using Google Docs for online collaboration in the co-construction of knowledge. This collaborative tool facilitated the instructor's close monitoring of the students' progress, enabling the instructor to provide feedback and effectively assist the writing process. The students' self-assessments throughout the process enabled enhancement of the collaborative writing experience. The results indicate how to enhance coherence, writing quality, professional development and provide useful information concerning the optimal content knowledge, writing process and pedagogical methods needed for the successful integration of collaborative pedagogy.