The ownership of mobile devices among teenagers has increased distinctly during the COVID-19 pandemic. Looking at this phenomenon, its influence is inevitable in educational policymaking. While some are still reluctant to utilize the ownership of mobile devices as students learning support, some parties have begun to take advantage of this momentum by enacting the Bring Your Own Devices (BYOD) policy. The BYOD policy, which was initially implemented at the company, has become a trend in many schools. This study aims to discover teachers’ perceptions in one of the private schools in Makassar on the BYOD policy implementation for secondary school students. For the semi-structured interviews, nine secondary school teachers were selected as the participants. The transcripts were analyzed using thematic analysis, enabling the researcher to identify three emerging themes including (1) transformation in teaching and learning, (2) students’ behavior, and (3) the regulation of BYOD implementation. The results reveal that the participants perceived the implementation of the BYOD policy has positive and negative impacts on students’ learning, achievement, and behavior. At the end of this article, some recommendations for the better of BYOD policy implementation are presented.