This study investigated unmet health care needs and associated factors among patients with hypertension and those with diabetes. Patients were identified by medical professionals. Patients who did not take pharmaceuticals to treat their disease(s) were defined as those with unmet health care needs. Using data from 2005 National Health and Nutrition Examination Survey, 3,635 hypertension patients and 1,431 diabetes patients were analyzed. A multivariate logistic regression analysis was employed to examine factors associated with unmet needs. Overall, 16.6% of hypertension patients, 20.3% of those with diabetes presented unmet needs. Common factors associated unmet needs for both hypertension and diabetes were sex, insurance type, self-reported health status and length of disease. Study findings suggest that hypertension and diabetes should be treated in early stage and further study is needed to examine the reasons for unmet needs to improve patient`s status effectively.