The purpose of the study was to investigate the effective implementation of instructional supervision practices in secondary schools of Hawassa City Administration in Ethiopia. The study focuses particularly on the practices and roles of supervisors in the implementation of instructional supervision, and the factors affecting its implementation in secondary schools. Basic questions related to the availability of instructional supervision strategies and their implementation, the roles of instructional leaders, perceptions of instructional supervision, and challenges for proper implementation of instructional supervision were raised. In addition, strategies for strengthening the effective implementation of instructional supervision were also addressed. The study was framed within the Theory of Change in Teachers’ viewpoints on instructional practices. In fact, there is a strong link with the instructional leadership strategies and the role of supervisors for the effective implementation of instructional supervision practices. The Instructional Supervision Model was used as it integrates the activities of instructional supervision in the schools. Moreover,this study reviewed global perspectives on educational supervision and provided an overview of the study context with an emphasis on improvement of instructional supervision. Philosophically, this study followed the pragmatist research paradigm, employing mixed research approaches; it also employed an explanatory sequential design in which both quantitative and qualitative data were collected simultaneously, interpreted separately and combined at the time of discussion for better understanding of the problem. Data were gathered from 160 supervision teams (vice-principals, senior teachers, unit leaders and department heads), 185 teachers. In addition, 14 principals and supervisors took part in interviews. One focus group discussion was also conducted with the city educational experts. Data were gathered through survey questionnaires, semi-structured interviews, FGD question guides and document reviews. Quantitative data was analysed through the descriptive approaches such as percentage, mean, grand mean and inferential statistics, known as standard division and t-test. Qualitative data collected through interviews and FGDs was summarised through thematic and narrative techniques, and finally triangulated. The results indicated that the quantitative and qualitative data supported one another. It was found that school supervision in line with strategies was inadequate. In addition, school supervision corresponding to the expected standards was not effectively done. The extent to which instructional supervisors design various intervention strategies so as to assist teacher’s professional improvement was insufficient. Evidence showed that instructional supervisors’ role in building effective relationship in schools was weak. Supportive, directive, conflict management and monitoring and supervising roles in the implementation of instructional supervision were also found to be inadequate. The teachers did not have enough support from supervisors in order to improve their instructional skills, and there was a negative perception of teachers about the implementation of instructional supervision. On the other hand, effective implementation of instructional supervision was hampered by a lack of qualified instructional supervisors, management skills, professional manuals, cooperation, and motivation for work and a lack of training and funding. Inadequate facilities and assignment of small number of supervisors hindered proper implementation of instructional supervision. Moreover, lack of commitment on the part of teachers and school leaders, lack of effective stakeholder support, lack of respect among stakeholders, lack of participatory supervisory approach and lack of adequate guidance between instructional leaders hampered instructional supervision. Based on the findings, instructional leaders, teachers, supervisors, school instructional supervision team and school communities need to be well equipped with basic knowledge and skills on the implementation of school instructional supervision, through pre-service and in-service training, experience-sharing programmes, seminars, workshops and discussion forums about the different approaches of supervision in order to enhance the professional growth of teachers and improve their instructional practices. This could help in fostering critical thinking and the problem-solving capacity of the supervisors. Moreover, the instructional leaders in schools need to plan for continuous training and orientation on the nature, practice and significance of instructional supervision. Suggestions were made to solve the factors that hinder proper implementation of instructional supervision. / Educational Management and Leadership / Ph. D. (Education Management)