The factors associated with students' academic performance may have been addressed but the impact of parental involvement continues to be a significant issue. Some schools in Kenya post poor results amid claims that parents are not supportive. This study examined the effect of parental involvement in homework on academic performance in public primary schools in Teso North Sub County, Busia-Kenya. The objectives were; to establish the types of homework assistance children get from parents, to ascertain the extent of parental involvement in homework and to examine the association between parental involvement in homework and school academic performance. All teachers, head teachers, pupils and parents in public primary schools were targeted. Thirty schools were sampled randomly from where 532 respondents (30 head teachers, 30 parents, 192 teachers and 280 pupils) were then sampled. Parents and head teachers were purposively sampled while teachers and pupils were proportionately sampled. A descriptive survey design was employed and data collected using questionnaires, semi-structured interviews schedules and document analysis. Quantitative data was analyzed using means, percentages and frequencies and qualitative data was reported directly. T-tests, Pearson moment correlation coefficient, and OLS regression coefficients were used to test hypotheses. The results indicate female parents were more willing to assist children in homework. Parents provided limited assistance in areas such as reading, writing and solving difficult sums. Parental involvement in homework positively correlated with school academic performance. The positive effect of parental involvement in homework disappeared when other variables were controlled for. It was concluded that since educational gains of parental involvement are noted and confirmed the significance of parents in educational processes. It was recommended that parents who don't assist children in homework should be sensitized to do so.