The study investigated the relationship between teacher professional development and students' academic performance in secondary schools in Kashari South, Mbarara City, Uganda. A correlational research design was employed with a sample of 152 respondents comprising teachers, head teachers, and students. Data were collected using structured questionnaires and analyzed using descriptive and inferential statistics, including structural equation modeling (SEM). Results revealed that 71.1% of teachers participated in professional development activities, with training frequency significantly correlated with student performance (r=0.67, p