BACKGROUND: Seasonality poses a considerable food security challenge in Ethiopia. Yet, measuring seasonal variations in food insecurity, particularly the dimension of food access, lacks an adequately validated tool. We therefore evaluated the performance of an adapted Household Food Insecurity Access Scale (HFIAS) to estimate seasonal variations in food insecurity (FI) among subsistence villagers in Ethiopia. METHODS: We employed a cohort study design using a panel of four repeated measurements taken in June, September, and December in the year 2017, and in March 2018. The study recruited 473 villagers from the drought-affected Wolaita area in southwest Ethiopia. The performance of the HFIAS was evaluated via internal consistency (Chronbach's alpha values) and criterion validation techniques. The set of criteria include: parallelism between affirmative responses to FI questions and wealth strata; dose-response relationship between FI and dietary intake; and also FI severity and household wealth status. RESULTS: This study revealed that the HFIAS had satisfactory performance in four repeated measurements. The likelihood of affirmative responses to questions about FI decreased with ascending wealth quintiles. We observed an inverse dose-response relationship between FI and wealth status, and between FI and household dietary diversity. CONCLUSIONS: The HFIAS showed an acceptable potential for measuring seasonal variations in FI in the study area. Our findings complement efforts to evaluate the scale's applicability in various settings, in order to promote cross-culture monitoring and comparisons. However, it required a careful adaption for contextual and cultural sensitivities.