The teaching of Kenyan Sign Language (KSL) as a subject in scholss for leaners with hearing impairment started in 2007 and was examined in 2010 after consistent poor performance in Kiswahili subject among these leraners wa realized. This research study, therefore, was carried out to evaluate the implementation of Kenya Sign Language as an examinable subject in primary school for learners with hearing impairment in Kenya and how it had influeneed their academic performance. The study adopted the descriptive survey design. The population comptised five schools and three hundred and sixty nine respondent from which a sample of five head teachers, fifty seven teachers and fifty learners was chosen. The study used purposive and simple sampling procedures; purposive sampling was used to select the five schools for learners with hearing impairment and the five head teachers while simple random sampling was utilized to select the fifty seven techers in schools. Information was gathered through questionnaires administered to the teachers whi;e head teachers and learners with hearing impairment were interviewed using face to face interviews. Observations and document reviews were also employed to crosscheck information. Quantitative data was analyzed using descriptive statics while qualitative data was done by coming up with catgories of responses, themes and sub themes . The study revealed that KSL performed above average and was the best subject as compared to the other subjects taught in schools for learners with hearing impairment. While SKL subject was found to be the best performed, the scores in certain subjects, such as Social Studies/CRE were disaml and performance of learnes with hearing impairment was still below average as compared to their hearing counterparts. The study also revealed that the major challenges which teachers and learners faced were lack of knowledge of KSL, limited vocabulary and inadequate learning and teaching materials for KSL. The study also revealed that teachers try to overcome these challenges by learning from the learnes, consulting from more exprienced teachers, and creating new sign for words which are new to both the teachers anf learners. The study recommends that more signs be developed to keep abreast with the trends and emerging issues in education of learners with hearing impairment. Further, the study recommends that the curriculum be reviewed to meet the needs of learners with hearing impairment. The research findings may guide teaching and learning in schools for learners who are hearing impaired as wll as improve their academic performance in Kenya.