The purpose of this study was to make the teachers in a particular private night high school participate in a School Based Professional Development program for their needs in educational technologies and adult learning theory so that the effectiveness of teachers in Private Night High Schools could improve. This was a case study including quantitative and qualitative data collected through Principles of Adult Learning Scale, Questionnaire of Educational Technologies, classroom observations, group meetings, and interviews. It was unfolded that knowledge level of teachers in terms of educational technologies was very low, and classroom use level of them was even lower. It was also revealed that those teachers had problems in adult learning theory. The findings of classroom observations and group meetings were consistent with the above-mentioned results. After needs assessment process, professional development (PD) programs on social media in teaching and adult teaching practices were developed and implemented in the target school. The teachers were asked about their views related to the whole process, and they acknowledged that they found it both informative and beneficial. [Note: The volume number (1) and issue number (2) shown on some pages of the PDF is incorrect. The correct citation for this article is v4 n1.]