There are limited studies on nursing diagnoses of the elderly living in nursing homes worldwide. This study aimed to define the most frequent nursing diagnoses in the elderly residents of a nursing home elder care and rehabilitation center. Seventy-four elderly individuals were included in the study. Data were collected using the "Elderly Individual's Introduction Form" between April 2007 to August 2007. The content of the form was based on a guide to gerontologic assessment, and Gordon's Functional Health Patterns. The nursing diagnoses (NANDA-I Taxonomy II) were identified by the 2 researchers separately according to the defining characteristics and the risk factors. The consistency between the nursing diagnoses defined by the 2 researchers was evaluated using Cohen's kappa (kappa). There was an 84.7% agreement about nursing diagnoses defined by the 2 researchers separately. The weighted kappa consistency analyses showed there was an adequate level of consistency (kappa = 0.710), and the findings were significant ( p < 0.0001). The most frequent diagnoses were ineffective role performance (86.5%), ineffective health maintenance (81.2%), risk for falls (77%), and impaired physical mobility (73%). The diagnosis of ineffective role performance was more frequent in patients with dementia (x(2) =10.993, df = 1, p = 0.001). There was a very significant relationship between dementia and the diagnosis of impaired verbal communication (x(2) = 32.718, df = 1, p = 0.0001). The relationship between mobility disorder and self-care deficit was also significant (x(2) = 19.411, df = 1, p = 0.0001). To improve quality in patient care, nurses should use nursing diagnoses with a systematic assessment and should help the elderly in health promotion or use of the maximum current potential.