Undernutrition is a quite common condition in the elderly, often identified using the mini nutritional assessment (MNA) test. The aim of this research was to study the independent value of the global and the subjective MNA questions to predict undernutrition according to the full MNA score, and to analyze the influence of gender and age on such items. A total of 22,007 Spanish people 65 years of age or older were evaluated using the MNA test. These data were obtained by trained community pharmacists. The subjective assessment was further evaluated on the basis of their sensitivity and specificity, by using receiver operating characteristic (ROC) curves. About 4.3% of the studied population were classified as undernourished according to the full MNA test. The subjective subscore (two questions) presented better predictive value than the global one (six questions). Indeed, 99.5% of subjects detected as well nourished using the MNA test were also correctly classified using only the two subjective questions. In the present study, it was identified that the two subjective MNA questions can be an efficient tool for a quick screening to rule out non undernourished subjects.