In an experimental, single case study, I investigate the disordered speech of a (4 1/2) year old Ndebele speaking child through a comparative study. A “cognitively” normal (41/4) year old Ndebele speaking child, is used as the control of the study. The aim of the investigation is to establish the speech sound system the subject is using and to test whether assessment protocols based on English, such as the Phonological Assessment Of Child Speech (PACS) framework by Grunwell (1985), suit the diagnosis of this subject''s speech disorder. The investigation is based on data collected from the subjects and the control through single 40-minute assessment sessions (one after the other) using probe tasks in the form of a picture alphabetic chart in Ndebele, designed for this study. Data collected is analysed according to Grunwell''s (PACS) framework. The PACS analysis established that the speech sound system of the subject of study differed from that of the control as a result of delayed acquisition of certain speech segments; this is evidenced by a reduced inventory of speech sounds when compared to the control..