This study examined the relationship between parental involvement and students' participation in primary schools in Rubanda District, Uganda, using Bubaare Primary School as a case study. Parental involvement is widely regarded as a determinant of pupils' attendance, motivation, and engagement in school activities, yet its practical influence in rural Ugandan settings is not always well documented. The study investigated the forms of parental involvement practiced by parents, the level of students' participation in classroom and co-curricular activities, and the relationship between the two. A descriptive case study design combining qualitative and quantitative approaches was adopted, and data were collected from 60 respondents comprising teachers, parents, and School Management Committee members using questionnaires, interview guides, and documentary review of school records. Descriptive statistics and thematic analysis were used to analyse the data. The results revealed that parental involvement at Bubaare Primary School was dominated by the provision of scholastic materials and payment of school requirements (80.0%) and home-based supervision of study time (60.0%), while attendance of school meetings (35.0%), volunteering (20.0%), and participation in the School Management Committee (15.0%) remained low. Pupils from households with higher parental involvement recorded fewer absences, higher homework completion, and greater co-curricular engagement than those with low parental involvement, establishing a clear positive relationship between parental involvement and students' participation. The study concludes that parental involvement significantly shapes students' participation and recommends parent sensitization, strengthened school-community communication, and the establishment of a functional Parent-Teacher Association.