In this research, the teaching styles of one biology teacher in each of three high schools in Rwanda are investigated. The purpose of the research is to find out how the adopted biology teaching styles impact on the teacher-student interaction and on the student‟s learning of biology in Kigali City in Rwanda. This research is descriptive and it is conducted in the qualitative research paradigm. The research approach used is a case study in three state and subsidised high schools. The research methods included interviews with six students and three teachers, classroom observations of three biology lessons per teacher and field-notes. The Rwandan education system has introduced a new approach to teaching i.e. the learner-centred pedagogy through an associative teaching style. In high schools, this new approach was first implemented in the school year 2011 but this implementation has been constrained by the scarcity of resources. Furthermore, some biology teachers, at the start of 2011, were not yet informed by educational authorities about the implementation of the learner-centred pedagogy. Thus, this research shows that some biology teachers are still using the teacher-centred approach; this is the case for Mr. Odumbe, whose teaching style is dominated by the transmissive approach, or the case of Mr. Kaggwa, whose view is that the educational authorities encourage the transmissive method of teaching. Even though the learner-centred pedagogy is encouraged because it fosters lasting knowledge and easy application of knowledge acquired in everyday life, the group work approach to teaching has been poorly managed and did not achieve desired results where it was used during this research. The participating biology students and teachers see the learner-centred pedagogy as slowing down the progression of teaching the content matter while the national examination covers the whole curriculum content. Therefore, although teachers were using different teaching approaches, once they are asked which approach they can choose to use, both students and teachers prefer to continue to use the teacher-centred approach in order to meet the content outcomes required in the national examination. Another result was that all participating students found their teachers supportive and nurturing and research is encouraged by all teachers regardless of their dominating teaching styles.