In Brazil, current information about breastfeeding indicators among indigenous living in the urban areas is lacking. This article describes the duration of exclusive breastfeeding and its associations with mother and child characteristics in a cohort of Terena infants. The study enrolled infants born between June 2017 to July 2018 (n = 42) and living in villages of the urban area of Campo Grande, Mato Grosso do Sul State, Brazil. Information was collected in four time-points. Variables on maternal sociodemographics and on maternal and child health characteristics were collected, respectively, during the antenatal and the first-month interviews. Variables on breastfeeding practices and bottle use were collected during the first-, six- and 12-month interviews. Associations were examined using Wilcoxon, Kruskal-Wallis, Pearson's chi-square, and Fisher's exact tests. The prevalence of exclusive breastfeeding duration to the ages of three and six months were, respectively, 50% and 11.9%. Compared to infants never introduced to bottles during the first three months of life, those bottle-fed had lower median duration of exclusive breastfeeding (15 versus 150 days) and lower prevalence of exclusive breastfeeding duration to the age of three months (22.7% versus 80%). Most Terena infants fell short of meeting the international recommended duration of exclusive breastfeeding until six months of age and suggested the negative impact of bottle use in the duration of exclusive breastfeeding.