The study was conducted in Tanzania using Njombe Region as a case study. The region is located in Southern Highlands; its land area is 21,299 Square kilometres, and its water area is 3695 Square kilometres. The government of Tanzania started to supervise secondary schools through a clinical supervision approach in 2008. The essence of employing a clinical supervision strategy is to enable teachers to develop fundamental shifts in how they view themselves as professionals in the teaching profession. This study was a mixed-methods and multiple cross-sectional case research design. Ninety-four participants filled in the questionnaires, and twenty-eight participated in the semi-structured interviews and FGDs. The SPSS version 25 supported the analysis of quantitative data, while qualitative data, on the other hand, were analysed through content analysis. The study found that effective communication and cooperation were positive factors influencing effective clinical supervision in schools. Consequently, teachers developed positive teaching emotions. The study found that textual teaching and learning materials, teaching workload and schools’ infrastructure were negative factors for clinical supervision practices. As a result, teachers developed negative teaching emotions. The study concludes that effective communication and teachers’ necessary supervisory cooperation significantly strengthened school heads’ clinical supervision practices, and the shortage of textbooks, teachers’ heavy workload, and a severe shortage of teachers' houses weakened it. Positive teachers’ emotions among teachers emerged as a result of the appropriate clinical undertaking. Negative teachers' emotions emerged from improper clinical supervision practices. The government is recommended to improve clinical supervision by supplying teaching and learning resources, balancing the class size and designing teachers’ housing services schemes. This article offers a practical understanding of factors that hinder and reinforce clinical supervision practices in Tanzania. A new insight brought by this article to the international communities, particularly Sub-Saharan countries, including the effects of clinical supervision on emerging teachers’ emotions. Future researchers are encouraged to design developmental research studies that construct standards framework for clinical supervision practices in the context of lower secondary schools. Educationalists are encouraged to set strategies and implement them by mitigating heavy teaching workload, inadequate physical infrastructure and shortage of textual teaching and learning materials.