The purpose of this study was to examine the usefulness of nursing diagnoses, based on the Omaha System framework, in explaining utilization of primary health care services in a Community Nursing Center (CNC). Utilization was defined as the number of client visits at the CNC. Data were obtained from a total of 331 client records where the Omaha System taxonomy was used in the documentation of nursing diagnoses with each nurse/client encounter. Hierarchic regression analysis was conducted to examine predictors of utilization. Nursing diagnoses were significant predictors of utilization at the CNC above and beyond client demographics. These findings suggest that nursing diagnoses data may be useful in explaining clients' use of CNCs.