This study sought to investigate the relationship between supervision and performance of teachers in primary schools located in Kabira Sub County, Mitooma District, in Western Uganda. Regular and effective supervision of teachers has been identified as an important factor that influences their effectiveness in imparting knowledge and skills to learners. The research aimed to establish the current supervision practices employed by school leaders and examining officers in the sub county and how these impacts teaching standards. A correlational research design was used involving both qualitative and quantitative approaches. The target population included all head teachers, deputy head teachers, examining officers, and subject teachers working in the 20 public primary schools in Kabira Sub County. Primary data was collected through questionnaires distributed to 60 teachers which was augmented with interviews of 10 school administrators and 5 examining officers. Documentation such as teachers' lesson plans, marking schemes, and pupils' examination scores were also reviewed. Data analysis revealed that while supervision is conducted periodically, the practices are mainly fault-finding with little focus on guidance, support, and capacity building of teachers. Feedback after supervision rarely discusses teachers' strengths or ways to improve on weaknesses. Inadequate facilitation of supervisors also impacts frequency and depth of monitoring visits. The study shown that majority of the respondents 66 (55%) strongly agreed with the statement that supervision enhances teachers’ professional growth, followed by those who agreed with 41 (34.2%), 10 (8.3%) were not sure, 03 (2.5%) disagreed. None of the respondents strongly disagreed. The results imply that supervision is a great tool in improving teachers’ performance because it enhances teachers’ professional growth. Teachers reported feeling alienated, demotivated and uncertain in fully meeting their responsibilities in the classroom. Findings clearly showed that schools with supportive and progressive supervision had higher pupils' achievement levels compared to those that experienced fault-finding approaches alone. Teachers exhibited commitment, innovation and belief in learner-centered pedagogies when supervised in a positive and developmental manner. It is evident that the manner of supervision directly influences teachers' effectiveness and learners' acquisition of conceptual skills.