Kiswahili is both a national and official language in the republic of Kenya. However, there are concerns that the poor performance in Kiswahili in national examinations is partially attributed to the laxity in the enforcement of the school language policy. Recent research has shown that Kiswahili is faced with lack of full implementation of language policy at various levels yet scholars have argued that language policy performs a substantial role in the enhancement of performance as well as the comprehension of the languages. The study objective was to establish drive or motive for the development of the school language policy in secondary schools. The study was conducted in 30 out of 300 public secondary schools found in Bungoma County. The respondents were 360 form three students, 90 teachers of Kiswahili and 30 principals. Cluster, stratified, purposive and simple random sampling techniques were used to sample the target groups. The questionnaire, FGD guide and document analysis guide were used to collect data. The quantitative data was analyzed using descriptive statistics which included the use of frequencies and percentages while the qualitative data was analyzed using the content analysis. The study established that the drive behind the development of the school language policy was almost uniform in all the sampled schools that participated in the study. It was further discovered that the way different schools enforced their school language policy impacted on the use of Kiswahili. In view of the above findings, it was recommended that the school administrators should ensure that their respective language policies should be fully enforced in order to meet its intended purpose and the school language policies should be well structured. It is hoped the finding of this study would help MOEST, principals of schools and teachers in formulating school language policy that aim at enhancing students’ achievements in languages offered in the curriculum.