The Cali Cancer Registry was started 50 years ago as a research program of the Department of Pathology of Universidad del Valle. It is presently continuing its strong silent but meaningful work, internationally recognized as the oldest most trustworthy and reliable source of data on descriptive epidemiology in Latin America. This is evidenced by the publication, of its results in “Cancer Incidence in Five Continents”, the most prestigious source of data on cancer incidence, since 1968 until the present time. Some population based cancer registries have started but had a premature death in Latin America. Some had been too ambitious in covering too large populations or whole countries. Others have been unable to maintain its modest but much needed economic support, reflecting the shortsightedness of national and international entities that provided the initial but not the continued funding. A few had followed the Cali Registry experience and have been able to survive economic difficulties experienced recently by some Latin American countries. Hopefully their initial success can be sustained and allow them to maintain is pioneering work. Such is the case of the Cancer Registry of Quito, operating very efficiently for 25 years, and the recently created Colombian Registries in Pasto, Manizales and Bucaramanga. The principal and most reliable sources of data are the histopathology reports. A first attempt to analyze data in a defined population was done in Medellin, when the Pathology Department of Universidad de Antioquia, founded and directed by Alfredo Correa Henao, represented the only source of histopathology diagnoses in the department of Antioquia. Such collection of data covered the years of 1944 to 1951 and was since the bases for publications in national and international journals. Later, in Cali, the histopathology diagnoses of cancer made in the pathology departments of the country were collected and presented the Third Congress of the Latin American Society of Pathology in Medellin in 1961.1,2 Dr. Harold Stewart, head of the Department of pathology of the National Cancer Institute in Bethesda, Maryland, was a special guest of the Society at the Congress. Dr. Stewart showed special interest in the data and brought them to William Haenszel, head of the Biometry Branch of the Institute. This was the beginning of a lasting and fructiferous association of Haenszel with the Cali Registry recognized by Universidad del Valle, which gave him the title of Doctor Honoris Causa.