The purpose of this study was to assess the knowledge, attitude and practice of personal hygiene among primary school pupils in Plateau state, Nigeria. The study was also guided by three (3) purposes, three research questions and three (3) hypotheses. The study employed ex-post-facto research design. The population of the study was 828,717 between the ages of 7 to 13 years pupils in Plateau state. A sample size of 400 was randomly selected proportionately through stratified sampling techniques, simple random sampling techniques and proportionate sampling. A closed ended questionnaire was used for the study. Descriptive statistics of frequency count, percentage, mean, standard deviation and one sample t-test were used to test the hypotheses of the study. Findings revealed that knowledge of school pupils towards personal hygiene in Plateau State is significant (t=5.207,p=0.021), because the probability value is less than 0.05 at 5% level of significance, the t-value value is 5.207 greater than 1.972 t-critical is at degree of freedom 392. The attitude of school pupils towards personal hygiene in Plateau State is not significant (t=1.341, p=0.081) as the result of the analysis shows that the probability value is greater than 0.05 at 5% level of significance, t-value is 1.341 is less than 1.972 t-critical at a degree of freedom 392 and practice of school pupils towards personal hygiene in Plateau State is not significant (t=1.291, p=0.39) as the result of analysis presented shows that the probability value is greater than 0.05 at 5% level of significance, the t-value value is 1.291 is less than the 1.972 t-critical at degree of freedom 392. On the basis of these findings, these recommendations were made. State Ministry of Health and other relevant organizations concerned with health care should intensify effort by creating health and Hygiene Promotion Programmes such as Talk shows and Seminars in Schools on the importance of hygiene through the formation of Health Club that would teach pupils on proper hygienic practices, and provide incentives for good hygiene practices. Though, the respondents have adequate knowledge of personal hygiene, there should be continuous education and sensitization through monitoring pupils by the School Authorities.