The purpose of this study was study was to examine teachers’ attitude towards open performance appraisal on pupils’ academic achievement. A quantitative and qualitative research survey design was adopted. The target population involved all primary school teachers, school quality assurers’, Human Resource Officer and District Education Officer, totaling to 1213. Random sampling technique was used to obtain 328 teachers and 33 head teachers, that is, 30% of the population, while the District Education Officer and Human Resource Officer and School Quality Assurance officers were purposively selected because they are few and the only existing ones. This study used semi structured interviews, questionnaires and documentary analysis for data collection. Qualitative data obtained was analyzed descriptively while SPSS software version 23 was used to analyze quantitative data. To ensure face and content validity of research instruments, two experts in the department of Education Administration Planning and Economics of Kisii University scrutinized the research instruments and validated them. A pilot study was conducted for reliability reasons. Anonymity, confidentiality, privacy and informed consent of the respondents were ensured. Findings of this study revealed that 65.52% of head teachers believed that teacher attitudes influences pupils’ academic success while 34.48% disagreed. It was concluded that positive attitude was key to pupils’ success. The study recommended that teachers and head teachers should be involved in setting goals and objectives of the performance appraisal process, The study adhered to the ethical consideration accordingly.