This paper analyses how writing a marketing plan is related to market research work, and how in writing that plan, students get acquainted with disciplinary literacy practices. Data gathered through class observation and interviews held with thirty students in their eighth semester of industrial engineering allowed us to prove the hypothesis that ongoing and authentic writing of specialized genres may help train students not only to better comprehend those genres, but also to develop mental habits or approaches to learning, doing, thinking, and behaving (Gee, 1996), related to their work within their disciplinary domain. We con-clude that situated writing practices may provide some framework to explain how academic genres work, and how knowledge can be reached and built, as well as how to develop identities that benefit learning specific domains.