ABSTRACT Objective To investigate the availability and price of fresh and ultra-processed foods in supermarkets before and during the Covid-19 pandemic in a mid-size city in the Brazilian state of Minas Gerais. Methods Ecological and longitudinal study. A proportionate stratified random sampling method was applied to supermarkets in the municipality. To assess the availability, variety, and price of fresh and ultra-processed foods, we applied the Estudo do Ambiente Obesogênico em São Paulo (ESAO, Obesogenic Environment Study in São Paulo, Brazil) Food Store Observation Tool questionnaire and calculated the Healthy Food Store Index. The audits took place from December 2019 to January 2020, and we returned to the establishments in September 2020. Descriptive analyzes, McNemar tests, paired Student's T or Wilcoxon tests were performed using the SPSS software, version 20.0, with a 5% significance level. Results Ten supermarkets were evaluated. The prices of oranges (p=0.012), bananas (p=0.043), apples (p=0.004), and onions (p=0.004) were significantly increased during the time frame. Sugar-free soft drinks (p=0.044), powdered drinks (p=0.032), and corn snacks (p=0.015) showed a greater variety of brands and flavors during the pandemic. The Healthy Food Store Index score was 9.50±0.85 before the pandemic and 9.00±1.15 during it. Conclusion The prices of some fruits and vegetables increased, and supermarkets sold a greater variety of ultra-processed foods. Such findings highlight the importance of assessing the consequences of the Covid-19 pandemic on the food environment.