The purpose of this article is to give a brief, yet concise overview of the current computational methods for predicting novel RNA-RNA interactions, that is interactions whose characteristic features we do not yet know. We start by briefly reviewing experimentally confirmed examples of RNA-RNA interactions before introducing computational methods for predicting RNA-RNA interactions. We will focus primarily on the interactions between different RNA molecules, that is trans RNA-RNA interactions, and will only discuss methods for predicting RNA structure, that is cis-only RNA-RNA interactions, where this helps to gain a better understanding. We conclude by discussing the merits of the different approaches and provide an outlook on probably and desirable future developments in the field.