This study investigates about the underlying factors that contribute to the failure of Language Policy implementation in the teaching of Kiswahili in Uganda’s primary schools. It was done in Kampala Central Division, Uganda. It was designed to address three major issues: to examine the historical background on the problem of language policy, in the teaching of Kiswahili in primary schools; to find out the current state and challenges affecting the teaching of Kiswahili and finally suggested practical recommendations for the improvement of Kiswahili teaching. The study purposely selected 27 interviewees from 8 schools and representatives from the Ministry of Education and Sports. The study also applied the documentary analysis technique to the data collected. The use of Revised Four- Fold Model (1983) championed by Haugen, provided a guiding theoretical framework that helped the study to achieve its desired findings. The findings of the study reveal that, pockets of Kiswahili language exist particularly in the army forces, music industry, trade, in higher institutions of learning, and in documents like the Uganda’s constitution of 2005, which declared Kiswahili as a second official National language of Uganda. The National Curriculum Developers’ Documents (2000, 2003, and 2008) also prescribes under volume Two, the teaching of Kiswahili as a subject in all Uganda’s primary schools beginning from standard Four to standard Seven. However, to a certain extent what is on paper contradicts what is in practice. The findings affirmed that despite the 11 years since the promulgation of Kiswahili teaching policy, the programme appears to be just beginning with a pilot scheme in the making, implying that the implementation is relatively very slow due to the numerous setbacks like lack of clear-cut policy, Negative attitude of the people towards Kiswahili, inadequate funds to finance the programme, lack of teaching personnel, inadequate teaching material resources and question of language choice among others. Using a literature review and research findings, this dissertation calls for greater resource allocation, political will and clearer policy objectives to achieve the aims of an effective Kiswahili teaching policy in Uganda’s education system. The study concludes that, if all the identified hindrances were eliminated by applying the proposed recommendations, then the implementation of Kiswahili teaching policy would be improved, leading to a common language that can foster unity among the people of Uganda.