This study investigates the nature of the acoustic variation in sequences of identical affricates produced by Polish learners of English. In both English and Polish sequences of identical affricates occur across word boundaries, but only in Polish do such sequences also occur root internally and across morpheme boundaries. In Polish sequences of identical affricates are manifested variably both by rearticulation of both affricates and by articulation of a single affricate but with lengthened duration of either the stop or the fricative. To investigate their English, the subjects performed two tasks: repetition of 12 English sentences and orally responding to 17 multiple choice questions. The task produced significant cross-speaker differences in the phonetics of the geminates, differences correlated with differences in their proficiency levels in English. The more Polish-like singly articulated long affricates were produced by 22% of the intermediate speakers but by 48% of the advanced speakers, the opposite of what one might expect. The intermediate speakers appear to have paid more attention to the phonetics of the English cues, thus producing more fully rearticulated affricates; the more advanced speakers appear to have paid less attention to the phonetics of the cues, thus reverting more to the norms of Polish pronunciation.