The goals of this study were to evaluate the accuracy of nurses' predictions of rehabilitation potential in older adults admitted to inpatient rehabilitation facilities and to ascertain whether the addition of a measure of executive cognitive function would enhance predictive accuracy. Secondary analysis was performed on prospective data collected for 362 Medicare beneficiaries enrolled in a national, multicenter study of rehabilitation outcomes. Ordinary least squares regression analysis was performed. Nurses' admission prognoses for rehabilitation potential predicted patients' functional status for observed activities of daily living upon discharge (r = 0.20, R{superscript 2] = 0.04, P less than 0.001). The addition of a measure of executive cognitive function, the Behavioral Dyscontrol Scale, significantly enhanced the variance explained by the model (r = 0.48, R[superscript 2] = 0.23, P less than 0.001). Nurses' prediction of functional outcome for hip fracture patients was significant (r = 0.26, R[superscript 2]=0.07, P less than 0.001). Predictions for patients with medical-surgical diagnoses did not achieve significance (r = 0.12, R[superscript 2] = 0.02, P = 0.13). The findings show the independence of nursing prognoses and the level of executive cognitive function, and suggest that inclusion of this measurement of executive cognitive function may significantly enhance the accuracy of nursing prognoses. Development and implementation of related nursing education might be warranted. Further research is needed to ascertain the best method to introduce assessment of executive cognitive function into the rehabilitation environment.