This study examined the production of English consonants by native speakers of Italian. The 240 adult native Italian speakers of English who participated had begun learning English when they emigrated to Canada between the ages of 2 and 23 years. Word-initial, word-medial and word-final tokens of English stops and fricatives were assessed through forced-choice judgments made by native English-speaking listeners, and acoustically. The native Italian subjects' ages of learning (AOL) English exerted a systematic effect on their production of English consonants even though they had lived in Canada for an average of 32 years, and reported speaking English more than Italian. In all but two instances, one or more native Italian subgroup defined on the basis of AOL differed significantly from subjects in a native English (NE) control group. The AOL of the first native Italian subgroup to differ from the NE subjects varied across consonant and syllable position. The results are discussed in terms of hypotheses proposed in the literature concerning the basis of segmental errors in L2 speech production. © 1995.