Recent spikes in staple food prices resulting from the invasion of Ukraine have once again highlighted the difficulty faced by low-income countries that rely on imports for a substantial portion of their food supply. To better understand which countries are most affected by higher world food prices, we propose a food import vulnerability index (FIVI). One version of the index describes the vulnerability of each country to higher world prices for each of 15 major staple foods. Another version of the FIVI is a national index, aggregating across the 15 commodities. Both are based on three components, the caloric contribution of the commodity(ies) in the national diet, the dependence on imports, and the level of moderate and severe food insecurity in the country. The values of the FIVI are calculated for 2020, the most recent year for which data are available. The results indicate that countries are most adversely affected by increases in the world price of wheat, rice, and maize, followed by sugar, and vegetable oil. This is because the five commodities listed are both major contributors to the diet in many countries and because countries often depend on imports for a large share of the domestic requirements of these foods. Yemen, Djibouti, and Afghanistan are most vulnerable to increases in world wheat prices, while Liberia, Gambia, and Guinea-Bissau are particularly vulnerable to spikes in rice prices. In the case of maize, Zimbabwe, Lesotho, and Eswatini have the highest vulnerability score. These results should help policymakers and development partners target their efforts to reduce food import vulnerability through policies and programs to strengthen resilience.