Abstract: The purpose of this study is to investigate if there is any correlation between college students’ engagement in online social networking activities and their writing for academic purposes. Facebook is chosen as a typical representative of the social networking technologies college students use. The study also investigates students’ and their instructors’ perceptions about the use of Facebook and its influence on students’ academic writing. Both quantitative and qualitative data were collected and analyzed. Although no significant correlations are found between participants’ Facebook engagement and most aspects of their writing performances, the results of the study are still revealing about college students’ Facebook use, characteristics of their academic writing, gender differences in both aspects, and their perceptions about online social networking and academic writing.