Upper respiratory infection (URI) is a major cause of morbidity and mortality in infants and toddlers in developing countries. The high infant morbidity and mortality rates in Indonesia are associated with the low exclusive breastfeeding rates. Breast milk is a natural drink for newborns in the first month of life and is beneficial not only for the infants, but also for the mothers. The aim of this study was to determine association ofexclusive breastfeeding practise and URI in infants aged 6–12 months. This study used a case-control design, and cluster random sampling was done. The study consisted of 162 cases and 162 control subjects aged 6–12 months. The study was conducted from December 2009 to June 2010 in Kampar District. Data analysis included univariate, bivariate, stratification, and multivariate with logistic regression. Results found that infants who were not exclusively breastfed were 1.69 times (95% CI: 1.02–2.80) more at risk of URI compared with those who were exclusively breastfed after controlling for the presence of a smoker at home and immunization.