ABSTRACT: Nigeria is a member of the British Commonwealth, having once been a colony of Britain. The English language that developed as a result of the contact with Nigerian indigenous languages over three or more centuries, is the standard British variety mediated by some Nigerian linguistic colour. It can therefore be described as distinctly Nigerian, but British norm‐dependent. Years of political, social and economic interaction between Nigeria and the USA have motivated an increasing use of the American variety of English (in addition to British English) in Nigeria. This paper examines some of the linguistic features of the emerging Americanisms in Nigerian English, especially at the phonological and lexical levels, and attempts to account for these features. Findings point in the direction of a growing bidialectism ‐ American and British norms ‐ in Nigerian English. The paper also analyzes Nigerian usage quantitatively in relation to some sociological variables. It concludes that Nigerian speakers of English now face challenges much more complex than bi‐competence in the language.