This study explored the relationship between performance appraisal practices and staff performance in Universal Secondary Schools in Rubaga Division, Kampala District. The study was guided by the following specific objectives; i) To examine the relationship between performance planning and staff performance, ii) To analyse the relationship between performance monitoring and staff performance, and iii) To examine the relationship between performance evaluation and staff performance in Universal Secondary Schools in Rubaga Division, Kampala District. The study employed a correlational research design with a mixed research approach. A sample size of 76 respondents was considered constituting of head teachers and teachers from the three selected universal secondary schools in Rubaga division. Both descriptive analysis and inferential analysis were employed to provide answers to the study phenomenon. The study revealed that performance planning has a strong positive and statistically significant relationship with staff performance in universal secondary schools in Rubaga division, Kampala district. The study also revealed that performance monitoring has a strong positive and significant relationship with staff performance in universal secondary schools in Rubaga division, Kampala district. Further, the study revealed that performance evaluation has a strong positive and statistically significant relationship with staff performance in universal secondary schools in Rubaga division, Kampala district. Therefore, the study concludes that performance appraisal practices in terms of performance planning, performance monitoring, and performance evaluation have a statistically significant association with staff performance in universal secondary schools in Rubaga division, Kampala district. Therefore, a significant increase in the different aspects of performance appraisal practices resultantly leads to an improvement in staff performance in universal secondary schools in Rubaga division, Kampala district. The study recommends that the school administrators should develop clear and quantifiable performance metrics to assess staff performance where possible as well as provide opportunities for staff members to develop the skills necessary to meet their performance goals such as formal training, mentoring, or on-the-job learning which could contribute to an improvement in staff performance in universal secondary schools in Rubaga division, Kampala district.