The purpose of this study was to investigate the teaching strategies that teachers of English use to teach learners comprehension skills. This study was guided by Social Cultural Theory (SCT) by Vygotsky (1978), which emphasises that learning is a social process which occurs when a competent person (teacher) or peers interact in a psychological space called Zone of Proximal Development (ZPD). The theory emphasises on the use of tools as resources in the learning process such as the comprehension strategies. The researcher used a qualitative case study design to generate data. The data was generated from the following: form three teachers of English, learners, head teachers and an English Language Paper III Chief Examiner. The participants were purposively selected in order to get qualified and experienced teachers who could provide the data that was sought. Further, the data was generated through document analysis, oral interviews and classroom observations using semi structured questionnaire and checklist respectively. Besides, the data analysis followed the thematic procedure according to the procedure stipulated by Creswell (2009) and Cohen et al. (2007). The study firstly found that the teachers' knowledge of appropriate teaching strategies to teach learners comprehension skills was limited. Secondly, the study established that teachers used eleven research-based strategies but were used inadequately due to insufficient knowledge of teaching strategies obtained during initial teacher training and from experienced teachers. Lastly, during implementation, the teachers were not modelling or explicitly teaching the learners comprehension skills because they had insufficient knowledge. The study further established that the expected sources of teachers' knowledge, pre- and in-service training, experienced teachers and texts on language teaching did not help the teachers acquire the appropriate knowledge. The study, thus, concludes that the teachers failed to effectively teach their learners comprehension skills due to the fact that they did not have appropriate knowledge of strategies for teaching comprehension.