Addiction at old age has been neglected by medical science for a long time. In spite of continuous advancements, there are still large knowledge gaps, prejudices and insufficient treatment services. This work introduces recent findings on the topic addiction at old age and bridges a gap between addiction medicine and gerontology / geriatric psychiatry. Alongside the more common abuse of alcohol, sleeping pills and tranquilisers, the use of nicotine, pain killers and illegal drugs is also covered.Fundamentals, diagnose, clinic and therapy are described concretely and close to practice. Aspects of mental and physical developments in the ageing process linked with and relevant to addictions at old age are discussed extensively. Special emphasis is placed on the interrelation of the consumption of addictive substances and cognitive derogation / dementia.