In Victoria, almost one in six registered medical practitioners were over 60 years old in September 2006. Knowing when to give up practice is an important decision for most doctors and a critically difficult decision for some. Normal ageing is associated with some cognitive decline, although brighter, better educated individuals may be less at risk. Mild cognitive impairment (MCI) is associated with higher rates of Alzheimer's dementia. Medical practitioners with early dementia or MCI often lack the insight to accept that they are no longer able to practise safely. Doctors can accommodate cognitive decline by choosing to cease procedural work, allocating more time to each patient, using memory aids, seeking advice from trusted colleagues, and seeking second opinions. Medical Boards are responsible for protecting the public from unsafe medical practice. There are no agreed guidelines to help Medical Boards decide what level of cognitive impairment in a doctor may put the public at risk.