“To improve the care of older patients with cancer around the world” Older patients with cancer, particularly those older than age 70 years, have specific needs that are not present in younger patients. It is well established that the traditional oncology evaluation is not adequate and will fail to uncover many specific problems. Geriatric assessment will no longer be the purview of the geriatrician but will need to be incorporated into daily practice in all oncology fields. Therefore, all oncologists need to become well-educated geriatric oncologists. The International Society of Geriatric Oncology, or Société Internationale d’ Oncologie Gériatrique in French, hence the acronym SIOG, was founded in 2000 and was officially registered as a Not-for-profit organisation under the Swiss law in October 2012. SIOG is a multidisciplinary society, including physicians in the fields of oncology and geriatrics, and allied health professionals. SIOG has over 8000 community members in more than 90 countries around the world who care for above 4’300 000 older patients with cancer. The major risk factor for cancer is age, and with the aging of the world population, a major epidemiologic challenge is before us. The goal of SIOG is to foster the development of health professionals in the field of geriatric oncology, in order to optimize treatment of older adults with cancer. SIOG promotes efforts in 3 strategic directions: education, clinical practice & research through annual and regional educational events, advanced courses and e-learning, practice guidelines, scientific and advocacy publications, etc.