This study reconstructed the proto-phoneme of consonants for a subdialect in the central basin of the Pahang River. The length of this river is 459 kilometres, and the area in the centre part of the river was selected to perform comparative linguistics observations. Five research sites were selected for this study purpose, namely Kuala Tembeling (KT), Lada (LDA), Jeransang (JRG), Kedondong (DDG), and Bukit Nikmat (BMT), based on their distinctive phonological characteristics. The research sites were visited twice to ensure the authenticity of the gathered data. The data were screened to extract cognate words using Crowley’s framework. Crowley’s sound correspondence set (SCS) was employed to evaluate and extract proto-phonemes. After the phonemes were retrieved, the reconstructed proto-phoneme of Adelaar was used as a point of comparison. The findings revealed that Proto-Centre Pahang river (PCPr) has 18 ancient consonant phonemes (*p, *b, *t, *d, *k, *ɡ, *m, *n, *ɲ, *ŋ, *l, *s, *ɣ, *h, *c, *ɟ, *w, and *j). The distribution of these consonants is diverse and depends on the consonant type. A vocalic feature of PCPr, such as vowels and diphthongs, should be the subject of future discussion to arrive at definitive conclusions regarding phonological changes between PCPr and Proto-Malayic (PM).