This report describes the endline findings of an external evaluation of the Tayari preschool program. Tayari is an early childhood development and education (ECDE) pilot intervention in Kenya funded by the Children’s Investment Fund Foundation (CIFF). The RTI International implemented the pilot, in partnership with Kenya’s Ministry of Education (MoE) and the African Population and Health Research Center (APHRC) who evaluated the pilot. The program, which ran from November 2014 to July 2018, aimed to develop a cost-effective and scalable model of ECDE that would ensure that children who join Standard 1 are cognitively, physically, socially and emotionally ready to start, and succeed in primary school. The program focused on improving learners’ knowledge and skills in literacy, numeracy, health and hygiene as well as psychosocial skills. It targeted pre-primary (herein used interchangeably with preschool) school children in ECDE centers in four counties in Kenya: Laikipia, Nairobi, Siaya and Uasin Gishu. Both public and Alternative Provision of Basic Education and Training (APBET) ECDE centers were targeted in Nairobi while only public centers were targeted in the other three counties. As the program’s external evaluator, APHRC’s role in Tayari was mainly to assess the impact of the program on preparing children for primary school and to assess the cost-effectiveness of the program.