Phonetic imitation is a ubiquitous process in speech production. Speakers have a strong tendency to imitate their interlocutors both in a native and a non-native language. It is especially important in acquiring non-native speech, because it allows forming new sound categories. In the current study we investigated whether and to what extent Polish learners of English are able to imitate t-glottalization observed especially in British English. A total of 25 Polish learners of English imitated English models' productions with t-glottalization that were subsequently compared to their default productions (pre-test) and post-exposure production (post-test). The results showed that the participants successfully imitated t-glottalization after the exposure to the model talker. The generalization effect was limited in its magnitude in that only some of the non-imitated words had traces of glottalization. The results are discussed in terms of the differences in the implementation of glottalization in Polish and English and of how phonetic imitation informs second-language speech acquisition.