Discrimination of non-native contrasts often differs as a function of stimulus presentation direction. The present study examined these directional asymmetries by assessing the Perceptual Assimilation Model (PAM). Korean listeners completed a forced-choice identification test and a categorical AX discrimination tests on six English stop-fricative contrasts, /pi/-/fi/, /bi/-/vi/, /di/-/ði/, /pu/-/fu/, /bu/-/vu/ and /du/-/ðu/. The identification test results yielded uncategorized-categorized (UC) assimilations for /bi/-/vi/, /pu/-/fu/ and /bu/-/vu/ and category-goodness (CG) assimilations for /pi/-/fi/, /di/-/ði/ and /du/-/ðu/. The discrimination test results revealed that directional asymmetries in which performance was better in the fricative to stop direction than the reverse direction were found for both UC and CG assimilation types, inconsistent with PAM. These results suggest that in non-native stop-fricative perception directional asymmetries might be modulated by language experience.