Respiratory infectious diseases such as bacterial pneumonia and bronchitis are common and costly, especially in institutionalized and elderly inpatients. Respiratory infection is thought to rely in part on the aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which then multiply to cause infection. It has been suggested that dental plaque may act as a reservoir of respiratory pathogens, especially in patients with periodontal disease. However, the impact of poor oral health on oral respiratory pathogen colonization and lung infection is uncertain, especially in ambulatory, non-institutionalized populations. To begin to assess potential associations between respiratory diseases and oral health, data from the National Health and Nutrition Examination Survey I (NHANES I) were analyzed. This database contains information on the general health status of 23,808 individual Of these, 386 individuals reported a suspected respiratory condition that was further assessed by a physician. These subjects were categorized as having a confirmed chronic respiratory disease (chronic bronchitis or emphysema) or an acute respiratory disease (influenza, pneumonia, acute bronchitis). They were compared to those not having a respiratory disease. Initial non-parametric analysis noted that individuals with a confirmed chronic respiratory disease (n = 41) had significantly greater oral hygiene index scores than subjects without respiratory disease (n = 193; P = 0.0441). Logistic regression analysis of data from these subjects, which considered age, race, gender, smoking status, and simplified oral hygiene index (OHI), suggested that subjects having the median OHI value were 1.3 times more likely to have a chronic respiratory disease relative to those with and OHI of O. Similarly, subjects with the maximum OHI value were 4.5 times more likely to have a chronic respiratory disease than those with an OHI of O. No evidence was found to support an association between the periodontal index and any respiratory disease. These results suggest OHI to have a residual effect on chronic respiratory disease of both practical and statistical significance.