Programmed ribosomal frameshifting, one of the alternative decoding events, occurs with the frequency significantly higher than the incidence of common translational errors of this type. In general, there are at least two motives involved in the frameshifting: the slippery sequence, where the shift of the ribosome takes place, and a cis element situated several nucleotides downstream of the slippery sequence, which enhances the event efficiency. This review is devoted to the mechanisms and examples of the frameshifting in a variety of organisms. The importance of this mechanism for their life cycle is discussed with respect to potential therapeutic applications.