A study was conducted in the Ethio-Swedish Children's Hospital and different schools and kindergartens in Addis Ababa to determine the prevalence of bacterial agents that are associated with acute respiratory infection in children from 1998-1999. A total of 883 subjects were studied, out of which 77% were cases from the Ethio-Swedish Children's Hospital and 23% were controls from different schools and kindergartens. From each case and control throat and nasopharyngeal specimens were collected. Culture and different biochemical tests were used to isolate the potential bacterial pathogens. Clinical findings like cough, difficult breathing and fever were correlated with laboratory findings. S. pneumoniae and H. influenzae type b were the most commonly isolated bacteria in both throat and nasopharyngeal specimens; 74% and 70% in the cases and 2% and 5% in the control groups, respectively. This paper discusses the association between throat and nasopharyngeal carriership of bacteria and acute respiratory infection in children in Addis Ababa.