Engaging each student in learning comprises a continuous challenge and concern for the contemporary teacher. Educational research confirms the alarming increase of the disengaged students, relating student disaffection to adverse effects on students' academic development. In the present research through one-on-one, semi-structured interviews, we investigate 80 Greek in-service kindergarten teachers' opinions with regards to the significance of engaging the disengaged students in learning activities in preschool environments. The interviews based on Creswell's (2009) interview model, incorporate open-ended and close-ended questions that offer a well-rounded view of the subject. Qualitative and quantitative data analysis of teachers' opinions show that engaging each disengaged preschooler has multiple benefits on students' academic development, class climate, and cohesion, and teacher's self-efficacy, as well. Specifically, teachers' engaging actions offer students the opportunity to develop their abilities, self-efficacy, and sense of belonging. The interviewees also recognise that increased student engagement levels decisively affect teachers-students' interactions, offering at the same time clear feedback to the teacher.