There has been a declining trend in performance among pupils in public primary schools at Kenya Certificate of Primary Education (KCSE) examinations since the introduction of automatic grade policy. The cause of this worrying trend is blamed on, among other factors, the implementation of the policy. The purpose of this study was to establish the influence of automatic grade promotion policy on pupils’ academic performance in Kirinyaga Central Sub-County. Specifically this study sought to establish; the status of adequacy of physical facilities in primary schools arising from the implementation of automatic grade promotion Policy in Kirinyaga Central Sub County, and the impact of physical facilities on performance of Pupils’ academic performance at KCSE among primary schools in Kirinyaga Central Sub-County. This study used descriptive survey research design and adopted a mixed method approach. The population of the study was 32 head teachers, 181 teachers and 2170 pupils; and a sample of 30 head teachers, 118 teachers and 325 pupils. Purposive sampling technique was used to sample head teachers while simple random sampling was used on the teachers and pupils. Questionnaires were used to collect data from teachers and pupils, while sampled head teachers were interviewed. Questionnaires were piloted in a neighboring Sub County using test retest method and reliable reliability index of 0.702 and 0.756 obtained for teachers’ and pupils’ questionnaires respectively. The questionnaires and interview guide were adequately validated and administered. Quantitative data is tabulated while qualitative data was analyzed thematically in line with the research purpose and to answer the research questions. The study established that there are inadequate physical facilities in primary schools in the study area arising from the implementation of the automatic grade promotion. It further found out that the facilities were not adequately maintained and therefore compromised learners’ health and safety, and hampered instruction. The study concludes that school physical facilities influence pupils’ academic achievement. The study recommends that; government and other stakeholders should provide adequate physical facilities in schools alongside complementary resources for effective implementation of automatic grade promotion policy, schools should institute routine schedule of maintaining the available physical facilities. It further recommends a similar study be carried out in other Counties and to engage a larger population and more variables.