Under-ascertainment of elderly cases in cancer registry data is a well-known problem. This article provides the cancer incidence in developing countries corrected for the under-ascertainment in elderly cancer cases (aged 65+). The original incidence rate by GLOBOCAN 2002 was 11% (men 15%; women 7%) under-estimated, so there were 6,462,000 new cancer cases (3,093,000 men; 2,737,000 women) in 2002 topping the original estimate by 632,000. This paper is the first attempt to quantify the under-ascertainment bias in the cancer burden of developing countries and opens the discussion on how cancer incidence could be corrected in this increasing part of the population.