This study examined how home-based factors influence the internal efficiency of primary schools in Bungoma North and Kimilili-Bungoma Districts in Kenya. The study found that parental level of education, occupation, income, and the language used at home influenced pupils' academic performance. Specifically, fathers' level of education was a significant predictor of pupils' performance, with pupils' KCPE scores improving by 16.973 points with higher paternal education levels. Home-based factors accounted for 6.1% of the variation in KCPE results.