Background: Many national organizations produce guidelines on dementia. The differences between these can be arbitrary and not evidence based. Objectives: The EuroCoDe project aims to develop a dementia guideline which provides a degree of harmonization of practice across European national boundaries. This may then become a vehicle for decision making at an European level. Methods: Guidelines for diagnosis and treating dementia were identified using searches of electronic databases, internet searches, searches of dementia organisations and guideline clearing house websites and contact with key organisations and experts in dementia from across Europe. In conjunction with Alzheimer Europe, a database was developed to: store abstracted information from dementia guidelines; allow users to search for and view guideline abstracts; and enable comparison between recommendations of different guidelines. A consensus recommendation for each area of practice (e.g. drug treatment of psychosis, diagnostic criteria to be used) was derived by referring to the recommendations of the national guidelines. This was then submitted for redrafting to a working group, before being submitted for wider consultation to a larger convenience sample of clinicians. The working group resolved disagreements by reference to the original national guidelines, and more recent high quality evidence. Results: Thirty-nine guidelines were identified using the above strategies. Of these: 8 were European English language guidelines; 14 were European non-English language guidelines; and 17 were non-European, English language guidelines. Guidelines were from two main sources, professional organizations and national health departments, and were primarily intended for use by medical professionals. Generally, recommendations did not differ greatly between guidelines. Funding arrangements clearly influenced some recommendations. There was a dearth of evidence relating to anything other than first line treatments. Conclusions: Many national organizations produce guidelines on dementia. The differences between these appear to be influenced by factors other than the available evidence.