To make a diagnostic of cancer in a young adult (15-30 years of age) has important physical, psychological and social implications. The most frequent cancers seen at this age are cancer of the thyroid, testicular germ cell tumours, 'melanoma, Hodgkin's lymphoma, non-Hodgkin lymphoma, leukaemia, cerebral tumours and sarcomas. Even if the prognostic of most of these cancers is excellent, treatments are difficult and often associated with long-term side effects. A multidisciplinary approach of these patients is essential. A long-term follow-up by a general practicioner or an oncologist is indispensable.