Research suggests there has been a cultural change in the disclosure of diagnosis with most evidence held in cancer literature. This article reviews how disclosure of diagnosis relates to the field of dementia. Practitioners' attitudes and practice are being discussed, as are the attitudes and views of carers, peer groups, and patients. Practitioners show great variations in practice, with only around 50% of clinicians regularly telling patients with dementia their diagnosis. The majority of carers also appear to prefer the diagnosis to be withheld from the patient with dementia. However, most practitioners and carers would wish to know themselves if they had the illness. Although in contrast, studies on the views of elderly peer groups show that the vast majority wishes to be fully informed, views of patients with dementia regarding the area of disclosure are still lacking. Factors influencing the decision to disclose the diagnosis, including the degree of certainty of the diagnosis of dementia, the degree of insight of the patient, and the severity of the dementia, are investigated. The advantages and disadvantages of disclosure and the ethical issues are examined, as well as when or whether and how to disclose the diagnosis of dementia. Flexible guidelines regarding the process of disclosure are introduced.