Introduction: At 1964, Antioquia Medica journal published the first original work of blood type frequencies in Medellin led by Dr. Alberto Restrepo Mesa, one of Hematology pioneers in Colombia; later there have been two important investigations in 1999 and 2006, however, there are not current reports. Objective: Establish the blood type frequencies in Medellin and the Valle de Aburra after 50 years of the first published investigation. Methods: An observational descriptive study was made, with a sample of 87.000 adult people of both sexes, without racial discrimination, who donated blood at the Hospital Pablo Tobon Uribe blood bank of Medellin (Colombia) between 2000 and 2009; and frequency of ABO and Rh blood groups was calculated. Results: Of the total donors, 90,7 % living in Medellin. The most frequent blood groups are O+ and A+ (52,1 % and 28,0 % respectively), according to the previous studies. Conclusions: At the last 50 years, there is no evidence of a significant change in blood type frequencies in Medellin, despite the demographics changes on these years.