This study seeks to determine the role some factors, intervening in the development of the of English phonology, play in shaping the speech of bilingual students in Cameroon, in general, and those of the University of Yaounde I, in particular. Emphasis is laid upon the effect of four factors which are assumed to affect bilinguals' attainment in the production of English consonants, vowels and word stress. These factors are age, previously spoken language(s), formal instruction and motivation. Three tests for data elicitation were conducted on second year English-French and French-English bilingual students of the University of Yaounde I: Sentence Reading Style, Text Reading Style and Casual Speech Style. It follows from the analysis of speech samples that previously spoken languages are the factor with the highest toll on the bilinguals' speech. Age affects attainment very marginal in a multilingual setting like Cameroon. It also follows that a number of RP renditions are attested in the speech of some bilinguals. Two factors were said to explain this: formal instruction and motivation. Yet none of these factors could solely explain these speakers' speech.