The quest to strike a balance between learning in the classroom context and excelling in national examination in primary schools has remained a challenge to curriculum implementers for a long time. Proper application of learning domains in the classroom process is however very essential in determining the extent to which holistic leraning has taken place. The purpose of study was to assess primary school teachers' application of learning domains in classroom instruction in primary schools in West Pokot Country. Objectives of the study determine teachers' understanding oflearning domains, determine the extent to which learning domains were addressed in the classroom process in primary schools in West Pokot Country, examine teachers' use of Table of Specifications in prmary schools in West Pokot Country. the study was guided by priciples embedded in Daniel Stufflebeam's Context, Input, Process and Product (CIPP) Evaluation Model wich is a model for guiding formative and summative evaluation of a program. A Conceptual framework was also used to show the interplay between the variables under study. The study employed a descriptive survey design and adapted mixed methods approach in collection of data in a pragmatist philosophical paradigm. The study used multi stage cluster sampling technique wich combined both simple random and stratified proportionate sampling. A structured questionnaire was the main instrument of collecting quantitative data. Cronbach alpha was used to determine internal consistency of the instrument. An overall Coefficent of 0.7 was realized indicating that there was high internal consistency in the instrument. Classroom observation, interview and document analysis were used to collect qualitative data. The study found that theacher did not teachers did not understand what learning domains are and therefor did not apply then adequately ine the learning process. The study concluded that application of learning domains in public primary schools in West Pokot influences learning achievments oh pupils.The study recommended that supervision of schools be intensified to ensure that there is more teaching and learning.