Early childhood education is the foundation of basic education in Kenya. However, the low academic performance of early childhood teacher trainees in Kenya has raised concerns among the education stakeholders. The Kenya National Examination Council‘s results of pre-school teacher training colleges indicated that most teacher trainees achieved either referral or completely failed to meet course requirement. The purpose of this study was to assess the relationship between components of pre-primary diploma teacher education program and academic performance of trainees in Kisumu County Kenya. The objectives of the study were to; to investigate the relationship between training facilities and academic performance; determine the relationship between trainer‗s professionalism and academic performance; establish the relationship between utilization of teaching and learning resources and academic performance and to examine the relationship between quality control and academic performance among trainees in pre - primary teacher training colleges in Kisumu County in Kenya. Cognitive constructivism Theory by Jean Piaget was used to guide the study. The concurrent triangulation design within mixed method approach was adopted. The study population was comprising of 1150 teacher trainees from the 23 registered pre-primary teacher training colleges, 7 Sub county pre-primary coordinators and 23 college programs officers in Kisumu County. The study used Slovin‘s Formula to calculate the sample size of 297 for the trainees and a simple random sampling procedure was used to select them. However, saturated and purposive sampling technique was used to select 7 sub county pre-primary coordinators and 23 college programs officers respectively. Questionnaire was used to collect data from teacher trainees, while interview schedule was used to collect data from program officers and sub county pre-primary coordinators of ECDE. Descriptive and inferential statistics were used to analyze quantitative data while thematic analysis was used to analyze qualitative data. Trainers‘ professionalism, teaching and learning materials and adherence to quality control standards were found to be statistically significant and positively predicted the academic performance of trainee teachers. The study found that most of the pre-primary school colleges in Kisumu county were moderately prepared in terms of training facilities, this consequently impede good academic performance among the trainees. The study therefore recommend that both the national and county governments should put aside enough financial resources for revamping and adequately furnishing the preschool colleges with the teaching facilities. The study also recommended further research to investigate the impact of implementation preschool education policy guidelines on teaching of the teacher trainees with aim of improving quality of training in teacher training colleges.