This study investigated the impacts of the previous and current learning experiences of the student teachers on their microteaching practices. The study pursued threefold research goals: to diagnose the microteaching stance, to treat it, and to explore and evaluate the progress. The participants were 24 undergraduate third year student teachers attending the English Language Teaching (ELT) Department at a Turkish University. Two types of research were used for data collection: "ex post facto research" to scrutinize the previous learning experiences and teacher cognitions of the participants and "phenomenographic research" to specify their current performance in microteaching practices in terms of (1) professionally self-development; (2) sharing others' experiences; (3) developing educational aims; (4) enhancing skills development; (5) focusing on learners; and (6) negative impacts of microteaching. Depending on the ex post facto data, it was assumed that the previous learning experiences and teacher cognitions of the student teachers might have had some undesirable impacts on shaping their teaching perception. Drawing on the perspectives of the student teachers who were exposed to treatment process, it was noticed that the treatment process assisted them to participate in a more constructive and functional manner in microteaching practices.