Background and Objectives: This study was aimed to identify the distribution patterns of ABO and Rh-D blood group among the women hospitalized in our hospital Pio X, during the years 2009-2018 in order to observe the new distribution in the Milan population. Materials and Methods: We collected and analyzed 13223 blood samples and evaluate the distribution of ABO and Rh (D) antigens also by ethnic groups. Results: We observed that during last ten years the resident population is changed; the percentage of Caucasian (alias Italian) women is reduced, while the percentage of women belonging to other ethnic groups is increased. This different composition of resident population reflected what we observed in ABO and Rh distribution. We noted that the actual Milan population is formed by women of about 10 % of African, 8 % of East Asian, 8 % of Iberia-American, 5 % of east Europe, and around 70 % of Caucasian. We observed this difference in a new distribution of ABO group and Rh antigens. Conclusion: Our data suggest that the Milan population is composed by Caucasian people but also by mixed marriages between Caucasian and East Asian population children, in particular. This fact could lead an important remix of blood genes that explained the different distribution also in the actual Milan resident population.