The significance of policy guidelines in informing practice of any programme cannot be overemphasized. How effectively this policy is implemented has a bearing on the quality of teaching and learning and eventual acquisition of skills. Despite the National Pre-Primary Education Policy Standard Guidelines being in place from 2018, there is still an outcry over low achievement in terms of core competencies. The purpose of this study was to assess the implementation of the Kenya pre-primary education policy guidelines as a predictor of acquisition of basic core competencies among pre-primary learners in Kisii county, Kenya. The study objectives were to; establish the relationship between pre-primary centres’ implementation of the Policy Guidelines on the provision of infrastructural facilities and the acquisition of basic core competencies among pre-primary learners, establish how implementation of policy guidelines on infrastructure affect acquisition of core competencies among pre-schoolers, determine the extent the implementation Service Providers Suitability pre-primary policy guidelines predicts the acquisition of basic core competencies among pre-primary learners, examine the influence of pre-primary centres’ implementation of the pre-primary Policy Guidelines on food, health and safety on the acquisition of basic core competencies among pre- primary learners and find out the relationship between pre-primary centres’ implementation of the Policy Guidelines on teacher child ratio and the acquisition of basic core competencies among pre-primary learners. The study was guided by mixed research design with qualitative and quantitative methodologies and anchored on Bronfenbrenner’s bio ecological systems theory (1979). The study target population consisted of 37 primary head teachers and 111 pre-primary teachers, one Quality Assurance Standard Officer of Kisii Central Sub- County. Census approach was used to include all the targeted respondents in the study. The face, construct, and content validity of the instruments was determined through the expert judgement of university supervisors. Reliability of the research instruments was determined by test-retest method and a reliability coefficient of 0.734 was reported. Questionnaires, interview schedules, and document analysis was administered to collect data. Quantitative data was analysed using descriptive statistics such as frequencies and percentages and inferential statistics such as Pearson correlation coefficient. Qualitative data was analysed using thematic analysis. The study found that most of the ECDE centers in Kisii Central Sub- County had not fully implemented the national pre-primary education policy guidelines of 2018 because majority of them still had poor ECDE infrastructural facilities, including lack of spacious and well-tendered classrooms, playground, toilets, and furniture. However, most of the service providers such as ECDE teachers, head teachers and centre managers were well trained to administratively take care of the learners. Most of the ECDE centres did not have properly structured food, health and safety systems. Lastly, most of the ECDE centres were understaffed hence the teacher-child ratio was still a big problem in most of the centres. The Ministry of Education in collaboration with the parents and other education stakeholders should ensure that ECDE infrastructural facilities, including spacious and well-tendered classrooms, playgrounds, toilets, and furniture are available in adequate amount and also in good condition. They should also ensure adequate funding to the ECDE centers to facilitate optimal implementation of the national pre-primary education policy guideline of 2018. The ministry of education in the county governments should hire more trained ECDE teachers to limit the teacher-child ratio and encourage good learning among children. This will also encourage good teacher child contact and conform with the teacher child ratio policy and guidelines in pre-primary schools.