The current state of knowledge regarding the safety of measles, mumps and rubella vaccine (MMR) is reviewed. Although there are known adverse reactions to the vaccine, the majority are relatively minor and have no long term consequences, and those that do have long term consequences are extremely rare. Contraindications, known adverse reactions that may follow MMR immunisation, publicised adverse events for which a causal association with MMR has not been established, and the complications that may follow an infection with wild-type measles, mumps or rubella, are discussed. The article also discusses, with examples, the misleading information that can be obtained on the internet and in the public press. It is vital that the general public have an understanding of the great benefits and low risks associated with the use of MMR vaccine, because it is important that they consent to the administration of MMR vaccine to their children in order to ensure the success of universal immunisation programmes and the control of measles, mumps and rubella. Therefore, it becomes increasingly important for health professionals to use innovative education methods to promote immunisation and counteract the incorrect and misleading information that is readily available on the internet and in the media.