The Afro-descendant population represents 10.6% of the inhabitants of Colombia (42 million) and 82% of the residents of the Department of Chocó (505 thousand) (DANE general census 2005; http://www.dane.gov.co). The present population status of the Department of Chocó is the reflection of its historical past, initially inhabited by several Native American communities and later by both Europeans and Africans who arrived during the colonization process in the American continent. This work determined the ancestral component of these three ethnic groups in a population sample of 120 Afro-Colombian individuals born in the Department of Chocó. The ancestral components were calculated according to the methodology described in Pereira et al., 2012. The software STRUCTURE v2.3.4 was used to estimate the African, European and Native American admixture proportions in the Afro-Colombian samples. As parental populations, the genetic profiles of 322 individuals (Africans: 105 Europeans: 158, Native Americans: 59) and 42 Native American individuals were used. The MD406 marker was the only one that showed significant deviation in the Hardy-Weinberg test. The ancestry analysis for this population revealed a main African contribution (76%) with a minor contribution of European and Native American ancestries, 17% and 7%, respectively. These findings are correlated with the historical records of this Pacific region.