BACKGROUND Lower respiratory infections (LRI) are an important cause of morbidity, mortality, and hospitalization of nursing home residents, yet treatment recommendations have primarily been based on the minority who are hospitalized. We sought to prospectively evaluate risk factors for mortality from LRI in community nursing home residents. METHODS We studied residents of 10 central Missouri nursing homes (910 beds) from January 1994 to September 1994. Attending physicians authorized nurse evaluations of ill residents who showed symptoms of an LRI. Those residents who met the study definition of LRI received a more detailed assessment and follow ups at 30 and 90 days. RESULTS The 231 evaluations identified 141 LRIs in 121 individuals. Sixteen (11%) residents died within 30 days of evaluation. The most important univariate predictor of 30-day mortality was severe activities of daily living (ADL) dependency (relative risk = 8.8, 95% confidence interval, 2.55-30.1). Several other clinical and laboratory findings were also significant predictors. In multivariable logistic regression, ADL dependency, respiratory rate, and pneumonia on chest radiograph independently predicted mortality; the model showed good discriminating ability (c = .83). CONCLUSIONS For nursing home residents with LRI, ADL dependency is an important mortality predictor. Further research with a larger sample should lead to a useful prediction rule for outcome from nursing home-acquired LRI.