Background: Among the cognitive markers of Alzheimer’s disease (AD), semantic and phonemic verbal fluency tasks seem to be an early indicator of deterioration. The aims of this study are 1) to evaluate both types of Verbal Fluency in the early stages of AD in order to know which of them deteriorates earlier and, 2) to investigate if Verbal Fluency Tasks can help to differentiate between patients with Mild Cognitive Impairment (MCI) who will progress to AD two years later (progresses) and those who do not (non-progresses). Method: A Verbal Fluency Task was administered to 25 patients with MCI and their respective control subjects. All patients underwent a neuropsychological evaluation twice in order to follow up their global cognitive status. The second time, 8 of them converted to AD. Results: On the one hand, Phonemic Verbal Fluency deteriorates earlier than Semantic Verbal Fluency in MCI patients; on the second hand, although we found statistically significant differences between patients with MCI and AD in both type of fluency tasks, they were not found when comparing the performance of progresses and non-progresses. Conclusion: These results point to a greater impairment in Phonemic Verbal Fluency in MCI patients and its potential predictive capacity to predict conversion to AD.