A study investigated the extent to which native speakers (NSs) and non-native speakers (NNSs) of Portuguese understand implicatures in Brazilian television commercials in Portuguese. Subjects were nine Brazilian graduate students and 11 American students of Portuguese at the University of Illinois at Urbana/Champaign. Correct inference of the implicatures was measured by a multiple-choice test, followed by an oral interview. Results revealed that the NSs' interpretation of implicatures was very uniform, with an average of correct answers (93.3 percent). Conversely, the performance of the NNSs varied, with an average of 47.3 percent correct answers. This was found to be true even in cases in which the implicatures in Brazilian Portuguese operated the same as in American English. Analysis of the data suggest that each case of successful inference requires some specific knowledge that may not be equally shared among NSs and NNSs. It is recommended that the pragmatic competence of American learners of Portuguese be addressed in language instruction. (MSE)