This note examines changes in vulnerability to oil price increases over a five-year period ending in 2008. A decomposition analysis applied to one hundred and fifty-eight countries found that vulnerability had increased in eighty-two percent of countries, with more than half experiencing vulnerability exceeding five percent in 2008 and one fifth experiencing vulnerability exceeding ten percent. This document explores the background of the issue, and includes tabulation to indicate the countries with greatest vulnerabilities, decomposition results for Bank client countries in Africa, Europe and Central Asia, Latin America and the Caribbean, South Asia, and the Middle East and North Africa, and corresponding tabulation for non-IDA/IBRD countries.