Although there has been a plethora of research on how Communicative Language Teaching (CLT) has been implemented in instruction, few have examined how teacher's beliefs about CLT affects assessment of their students and peers. Thus, this study examined how English as a foreign language (EFL) instructors' teaching beliefs affected not only their instruction but also assessment practices. Nine EFL university instructors from Colombia first completed a teaching beliefs survey, designed to examine how beliefs about CLT influence instruction and assessment. They also completed a peer evaluation form, which was used to understand how they evaluated other teachers' EFL lessons. In addition, three instructors (1) participated in a semi-formal interview to further discuss their beliefs about CLT and instructional practices, and (2) submitted tests they had previously developed to evaluate their students. Data were analyzed qualitatively and highlighted the specific challenges instructors experienced in implementing CLT into their instruction and assessment. Study findings provide practical implications for employing CLT in Colombian university settings.