Undernutrition in pre-school children of West Pokot, Kenya is a book that tries to assess the nutritional status of children aged 2-5 years. This cross sectional comparative study had equal number of pre-school children from the pastoral and farming communities of West Pokot.Anthropometric measurements of weight, height and MUAC were used to assess the nutritional status of pre-school children. Dietary data was collected using the 24 hour dietary recall. Hellen Keller Food frequency questionnaire was used to assess intake of Vitamin A rich foods. Stunting, underweight and wasting were found to be high in both communities. Pastoral and farming communities were found to be food insecure at a certain time of the year. The months the communities experienced food shortage was found to be a strong predictor of malnutrition in pastoral and farming communities of West Pokot, Kenya. This study recommended that there is need to address nutrition education by the government of Kenya Ministries and relevant non-governmental organizations.