This paper compares pupils' academic performance between the private and public primary schools. The sample, made up of 240 pupils were randomly selected from the private and public primary schools in Ilesa East and West Local Government Council Areas of Osun State, Nigeria. Two instruments were used. A structured questionnaire and Pupils' Achievement Test (PAT) in three core-subject areas of the Primary School Curriculum namely: English Language, Mathematics and Social Studies. While the questionnaire was used to collect relevant bio- data of the respondents, the instrument on achievement tests (PAT) was used to collect data on students' performance in the three subjects involved in the study. Data were analyzed using frequency count, simple percentages and Z-test. Results showed that pupils in the private primary schools performed better than their counterparts in the public schools and therefore call for improvement in the public schools to enhance the learning opportunity of the vast majority of pupils attending the public schools.