<p>The language policy in Rwanda states that English is the medium of Instruction (MOI) to be used in the Education system following the 2008 Language shift. However, this change in the MOI brought about extreme challenges to both Rwandan teachers and learners. Moreover, the extensive day to day usage of Kinyarwanda, the local dialect, has greatly inhibited the use of English. This has adversely obstructed the use of the English language as a MOI and the curriculum implementation for over 20 years hence adversely affecting the teaching and learning process. The proficiency of the teachers who are meant to teach in the MOI is quite questionable; many realize the need to learn English while teaching or risk unemployment. As such, this study purposed to examine the teacher competency and teaching styles in use of English as a MOI in facilitating curriculum implementation in rural primary schools in Rwanda. Guided by the inter language theory and the Discrepancy theory, the study applied a descriptive survey research design. With a target population of 3,269, the study entailed a sample of 1470 randomly selected learners from Primary 4 to Primary 6, teachers and head teachers from 21 schools. The study used questionnaires, interviews, and observation to collect primary data. The study found that the teachers’ competency in using English language as MOI had significant influence on curriculum implementation in rural primary schools in Muhanga district and in the entire republic of Rwanda. The teaching styles factors positively and significantly influence the use of MOI in curriculum implementation when other factors are held constant.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0807/a.php" alt="Hit counter" /></p>