Only a third of dementia sufferers in Oxfordshire have been diagnosed with the condition, a charity claims.
About 7,300 residents live with the condition, but only about one in three are receiving treatment, Age UK Oxfordshire says.
The charity will release a report, A Tale Of Two Counties, on Friday at the Ashmolean Museum.
Chief executive Paul Cann said action was needed to stop the elderly being "pushed aside".
The report claims those living in wealthier areas live up to 10 years longer.
A 10-point action plan calls for a "council of elders" in every town.