Categorical perception of a synthetic /r/-/l/ continuum was investigated with Japanese bilinguals at two levels of English language experience. The inexperienced Japanese group, referred to as Not-experienced, had had little or no previous training in English conversation. The Experienced Japanese group had had intensive training in English conversation by native American-English speakers. The tasks used were absolute identification, AXB discrimination, and oddity discrimination. Results showed classic Categorical perception by an American-English control group. The Not-experienced Japanese showed near-chance performance on all tasks, with performance no better for stimuli that straddled the /r/-/l/ boundary than for stimuli that fell in either category. The Experienced Japanese group, however, perceived /r/ and /l/ categorically. Their identification performance did not differ from the American-English controls, but their overall performance levels on the discrimination tests were somewhat lower than for the Americans. We conclude that native Japanese adults learning English as a second language are capable of Categorical perception of /r/ and /l/. Implications for perceptual training of phonemic contrasts are discussed.