This research investigated the articulation of the twelve pure vowels of English by Nigerian undergraduates. The aim was to examine how the performance of the subjects was close to or distant from the L1 standard and how an elevated form could be achieved. Applied Linguistics and Descriptive Linguistics formed the theoretical base for the work. Ten informants coded A-Jwere chosen through purposive sampling method from the four levels (year 1 – 4) in the Department of English, Akwa Ibom State University to form the experimental group. A list of 12 sentences each of which had a word that contained one of the 12 pure vowels was given to the informants to read audibly. The reading was recorded using Infinix HOT10 T android phone. The reading was carried out unobtrusively. The recording was played back several times and scored. It was found out that the long front vowel /ɪ:/, the long back vowel /ɔ:/, the front short vowel /ӕ/ the central vowel /Λ/ and the short back vowel /ʊ/ gave the informants difficulty of realization. Suggested reasons for the poor performance included vowel length, following consonant, position of occurrence, nature of the word in which the vowel was tested and absence of a vowel in the L1 of the informants. The result of mispronunciation is distortion of information with adverse implication for international communication. Informants’ interest in the English Language and in international English or “amalgam” was advocated.