Education is a continuous lifelong process which starts as soon as one is born. Preschool education is basic to formal education and requires special attention because of its foundational significance. One of the content areas in preschools' curriculum is language activities. Learners are expected to be taught using instructional materials. However, preschool learners' achievement in language activities in Kisumu East sub-county has been below par. This has led to the question as to whether there are implications of instructional materials on preschool learners' achievement in language activities. The purpose of the study was to establish the implications of instructional materials on achievement of language activities among early childhood learners in Central Zone Kisumu County. The objectives include; implications of instructional materials on oral skills among early childhood learners, implications of instructional materials on reading readiness skills and implications of instructional materials on writing readiness skills among early childhood learners. Descriptive survey design study was adopted. The study targeted a total population of 42 preschools and 160 preschool teachers. A total of 12 preschools and 12 head teachers were selected for the study through stratified random sampling, where, 5 preschools were selected from public and 7 from private preschools. Data were collected through questionnaires, interview schedules and observation checklist. The reliability of the research instrument was tested by conducting a pilot study in one preschool from the .county where the questionnaires were subjected to a pre-test before its use in actual data collection. The study instruments were validated by two experts from the department of Special Needs Education and Early Childhood Development. Quantitative data was analyzed through descriptive statistics as percentages and frequencies while qualitative data was analyzed through thematic framework and presented basing on each study objective. The study findings show that learners taught using instructional materials had improved oral skills as compared to their counterparts who were taught without. The study also found that learners taught with instructional materials had improved reading and writing readiness skills as compared to learners without the materials. The study recommends that teachers should use the result to initiate conversation that maximize talk and build on oral language using well designed instructional materials. Further, teachers should be encouraged to select appropriate instructional materials that enhance children reading readiness which are based on the difficulty level appropriate for the learners to encourage reading readiness. Teachers should also ensure the continuous use of spelling lists as an instructional material is essential for learning how to spell. Teachers should explore different writing materials such as paints, leaves, clay, play dough and plasticine to aide learners in writing letters of the alphabet. Furthermore study should be done on factors affecting the availability of instructional materials on language activities among early childhood learners and availability of instructional materials on language activities among early childhood learners public primary schools for learners.