Abstract : Therapeutic adherence can be defined as the degree of concordance between the behaviour of a person in relation with drugs prescription and medical recommendations. It represents the ability of people to follow a treatment. Bad adherence is frequent in geriatric patients. The behaviour of the patient is important but the role of the prescriptor and distributor of the drugs should also be emphasized. A bad adherence is responsible for iatrogenic consequences, which has a great impact on the functionality of the old person, but also on the cost and organization of care. Therapeutic education, a standardised method to help the patient take care of his own treatment, must be developed. The aims and means should be clearly efined. The patient himself must be involved and human or material sources of help must be sought.