This article reports on the results of a research study which investigated the perception of English speech sounds by Hong Kong Cantonese English as a second language speakers. A total of 40 university English majors participated in one categorial discrimination task and two second language (L2) minimal pair identification tasks, which aimed at discerning the participants' perception of different English speech sounds. The results show that certain English speech sounds trigger more perception problems than others, but perception problems do not necessarily correspond to documented production difficulties. It is argued that learners' preconception of word pronunciations may be a contributing factor for their perception problems. The position of a sonorant consonant may also play a role in perception, but positional effects do not seem to be as significant in the perception of obstruents as in that of sonorant consonants. It is suggested that remedial teaching on both perception and production should go hand in hand to enhance learners' L2 phonology acquisition.