A competency-based curriculum has been adopted in the Kenyan education system. However, for learners with disabilities in regular schools, they would be learning using two separate programs, that is an inclusive education program and a competency-based curriculum program. Implementing the two programs simultaneously to this category of learners could be challenging. Therefore, this study focused on the teachers training in Special Needs Education influencing competency-based curriculum implementation for Early Years Learners with disabilities in primary schools. The study was premised on the theory of Complexity and Education by Davis and Sumara (2006), which holds that the fruitfulness and range of systems in which ambiguity and uncertainty occur, should be embraced, and accommodated during evaluation. The researcher employed concurrent embedded design based on the mixed-method approach in gathering data. The study’s location was Nairobi City County, Kenya. The target population was 368 participants and from this target, the study sampled 16 heads of schools, 48 teachers, and 2 Educational Officers who were the respondents. The instruments of data collection were semi-structured questionnaires, an observation checklist, and an interview schedule. The piloting of instruments took place in one school with a special unit. The instruments were only accepted as valid and reliable after the results of Cronbach’s alpha coefficient of r=.75. Data were analyzed through descriptive and inferential statistics. In addition, data were prepared and organized using Statistical Package for Social Sciences into percentages, mean, Skewness, standard deviations, graphs, and tables. The researcher tested the hypothesis by use of the chisquare test at a significant level of ? =<.05. Findings disclosed that teachers with either high or low levels of training in SNE had no significant association with the level of implementation of CBC for learners with disabilities in regular class. Most teachers were trained in primary teacher education and early childhood education and lacked expertise to work with learners with disabilities. Various categories of learners present in schools were: There were no (0%) learners with physical disabilities admitted to private schools. In regards to developmental disabilities, private schools had the least 2(5%) of the children with dyslexia. Learners with behavioral/emotional disabilities who were present in private schools included: ADHD 3(7.5%), CD 1(2.5%), as compared to public schools, which had ADHD 3(7.5%), ASD 2(5%), CD 2(5%). Regarding sensory impairments, the private schools had the least 1(2.5%), while public 5(12.5%). The Low vision in private was 2(5%), while in public they were 9(22.5%), albinism 2(5%) in private schools, and none (0%) in public schools. Over half (51.28%) of teachers reported that they have trained in Competency Based Curriculum implementation and could apply the skills in teaching learners with disabilities, while slightly lower than half (48.72%) had not received any training in CBC and were unable to apply the skills. However, the level of training as ether primary teacher, early childhood education teacher or special needs education was not a predictor of competency-based curriculum implementation in classes. The study recommended a mass training of teachers in special needs education in the area of early childhood education. The study also recommended a study of the similar nature in upper primary schools.