The paper approaches the issue of the representational nature of metaphors in public service announcements (PSAs) from the standpoint of semiotics. Firstly, it tries to set up a semiotic approach to defining PSAs and identify their characteristic features. The paper views PSA as a separate genre of advertising discourse aimed at solving a social problem or providing a more efficient means of doing or accomplishing something of societal importance. Semiotic description represents texts of PSAs as a coherent sign reality where the coherence is ensured by the intentions mentioned above. It is claimed that the informational discoverability of PSAs is of paramount importance to its intended audience and thus new ideas need to be presented in terms of things that everyone understands. Thus the primary vehicle for communicating intentions and the driving force behind the creation and production of original PSAs are most commonly metaphors.Secondly, the paper seeks to explain how different types of representations are related: a) to medium; b) to each other; b) to the whole text; c) to other texts; d) to participants (the sender and the receiver); e) to the world beyond them. Special attention is paid to the multimodality of the genre under study.Finally, the paper outlines how the deliberate combining of metaphoric representations of different types adds to the impact of PSAs on the target audience. It is substantiated that metaphors display unique functionality in conveying various aspects of reality, thereby increasing the informativeness of PSAs and engaging the wide target audience.