In the following literature review, I set out to show an analysis of the main developments regarding the study of in-service English teachers' (IELTs) knowledge. In the first part, I trace scholarly work regarding the topic at the national and international levels. I bring up both poststructuralist and decolonial perspectives to problematize the concept of teacher knowledge base (Shulman 1987, 2005). By means of research profiling and data base search, articles and trends related to the issue of teachers' knowledge were found. The analysis suggests that there are two core trends in the study of English teachers' knowledge in Colombian publications. The first shows that there are studies which revolve around backing up the concept of knowledge base. The second one shows that few studies take up a different perspective towards the study of English teachers' knowledge.