This study aimed to analyze the impact of phonological disorders on the speech intelligibility of learners with Down syndrome. The study was guided by the Theory of Natural Phonology by David Stampe. A descriptive study design was used. Piloting was conducted in one of the public primary schools with learners with DS to ensure the validity and reliability of the instruments. The study used the available population of 25 learners with DS and 10 teachers trained in special needs education who were purposely selected from public primary schools in Kasarani Sub-county. Data was collected through tests of phonology, speech intelligibility tests and questionnaires for teachers. Descriptive statistics such as frequencies and percentages were used to analyze quantitative data, whereas the qualitative data that was obtained from open-ended questions was analyzed thematically. The study established that learners with Down syndrome displayed consistent phonological error patterns that have been classified as a disorder. From the ordinal speech intelligibility index scale, 65% of the learners had severe speech intelligibility, 25% had moderate speech intelligibility, while 10% had mild speech intelligibility. Further, the study established that the speech intelligibility of learners with Down syndrome is impaired due to the presence of phonological disorders, which have been noted to affect not only the academics and classroom participation but also the social aspect of their lives, self-esteem and interaction with their peers. The study recommended that special needs teachers should be trained in identifying learners with phonological disorders and methods of assisting in bringing clarity to their speech, thereby positively influencing the intelligibility of the learners with DS. Trained speech therapists should also collaborate with teachers to assist them in developing IEPs that target academics and different aspects of communication in the case of language impairment, such as phonological disorders.<p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/soc/0771/a.php" alt="Hit counter" /></p>