New developments in molecular genetics have improved our understanding on a number of neurodegenerative dementias considerably, especially Alzheimer's disease and frontotemporal dementia. However, this explosion of information can be overwhelming to clinicians, making it difficult to integrate into regular clinical practice. In this article, we briefly reviewed our current understanding regarding causative genetic mutations and genetic risk factors on the major forms of dementia, which provided the background information for discussion in the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia. The principles of genetic counselling were applied. Guidelines and recommendations on the application of genetics in the assessment, diagnosis, and management of patients and families with dementia were summarized.