Ensuring proper hygiene practices among school-aged children is critical for safeguarding their health and reducing the spread of communicable diseases. This study evaluates and compares the hygiene knowledge and attitudes of pupils enrolled in public and private primary schools in Port Harcourt, Nigeria. Port Harcourt is a city of over three million people, and the most economic State in Nigeria outside Lagos. A cross-sectional survey design was employed, and data were collected from a stratified sample of two hundred and twenty (220) pupils using a structured, pre-tested questionnaire covering key domains of personal and environmental hygiene. Descriptive statistics were used to summarize pupils’ responses, while independent sample t-tests and chi-square analyses determined significant differences between the two school categories. The findings reveal notable variations in hygiene awareness and attitudes, with pupils from private schools demonstrating significantly higher levels of knowledge (58 percent) compared to 43 percent of public schools’ pupils (p = 0.0655). Attitudinal patterns also differed across both groups; private school pupils had a more positive attitude towards hygiene, with 73 percent showing a positive response, compared to 54 percent of public-school pupils (p = 0.00056), reflecting disparities in exposure, school hygiene infrastructure, and parental guidance. The study underscores the need for strengthened hygiene education programs, particularly in public schools, and highlights the importance of coordinated efforts between government, educators, and parents to promote healthier environments for children. Targeted interventions and sustained awareness campaigns are recommended to bridge the knowledge gap and foster positive hygiene behaviors among primary school pupils in Port Harcourt.