Malaria is an endemic disease in a large part of Colombia, and the city of Buenaventura reports one of the highest malaria infection rates. Some genetic variants confer resistance to malaria, such as the heterozygote for hemoglobin S (HbS) and the homozygous variant FYBES/FYBES of the Duffy gene. The aim of this work was the molecular characterization of these genes in an Afrodescendant population from the urban area of Buenaventura. A total of 819 individuals from a stratified random sampling in each of the 12 communities of this city were analyzed. Molecular analysis was performed using PCR-RFLP, and data analysis was performed using Arlequin 3.5, SPSS 20.0, and R 3.4.1. Frequencies of 3.1% and 72.2% were obtained for the S and FYBES alleles, respectively, with 6.1% AS heterozygous and 55% FYBES/FYBES homozygous genotypes. The highest percentages of the resistant genotype (genotypic combination AA*FYBES/FYBES) were found for the 13–27-year age group (8.2%) and communities 1 and 3 (18% and 10.3%, respectively). Therefore, it would be pertinent to consider the remaining communities and age groups when performing epidemiological studies and preventive and health care campaigns on malaria in the urban areas of the city of Buenaventura.