The effects on audiences of irony in advertisements and of sarcasm in public information announcements were investigated in two studies. In advertisements for commercial products and services, irony was found in the use of negative captions where positive captions were expected. Sarcasm was used by placing a positive caption against a background displaying a harrowing picture. Such departures from common practice in the use of negative and positive wordings were regarded as inappropriate. It turned out that advertisements with ironic intent were appreciated more when the inappropriateness was re-interpreted correctly as irony (Study 1). Even so, irony and sarcasm may impede a proper understanding of the advertisements' informative intention. This has a negative impact on the assessment by an audience of the importance of the societal issues emphasized in sarcastic announcements (Study 2). © 2007 Elsevier B.V. All rights reserved.