We compared entorhinal cortex atrophy (ERICA) score vs. medial temporal atrophy (MTA) score’s ability to predict conversion from amnestic mild cognitive impairment (aMCI) to Alzheimer’s disease (AD) using magnetic resonance imaging (MRI). We hypothesized that ERICA would show higher specificity. Data from 61 aMCI patients were analyzed. Positive ERICA was associated with AD conversion with a sensitivity of 56% (95% CI: 30–80%) and a specificity of 78% (63–89%) vs. 69% (41–89%) SE and 60% (44–74%) SP for the MTA. Results suggest that ERICA is superior to MTA in predicting conversion from aMCI to AD in a small sample of participants.