Bearing the importance of perception in theacquisition of a second language and the differentfactors that may affect an accurate identification ofnonnative sounds, the main objective of this studywas to investigate perception of the Englishword-final /m-n/ by Brazilian learners. This contrasthas different patterns of phonetic realizationsacross languages, whereas they are distinctivelypronounced in English, in Brazilian Portuguese theyare not fully realized. Taking this phoneticdifference into consideration, this study mainlyaimed at investigating whether Brazilian learners ofEnglish were able to identify the native-likerealization of those nasals; and verifying whethervisual cues favored the identification of the targetconsonants.Two perception tests were designed andtaken by a group of Americans, as a reference forcomparison, and by a group of Brazilians. The bookreports and discusses the perception tests designedfor data collection as well as the results and itstheoretical and pedagogical implications. Studies ininterlanguage phonetics and phonology can provide atesting ground for phonological, phonetic and secondlanguage acquisition theories.