Global oil prices have risen markedly over the past 18 months, generating considerable speculation regarding their economic and social impacts. Cities that are highly dependent on petroleum for urban transport are likely to be most adversely affected by rising oil prices. Yet there has been little recent scholarly engagement with the socioeconomic implications of increasing oil prices. This paper develops a basic framework and methodology for assessing the socioeconomic 'oil vulnerability' of Australian cities. The paper demonstrates that there is wide spatial variability in the vulnerability of Australia's urban populations to rising fuel costs which may compound existing socio-spatial divisions and speculates on some underlying causal factors. The paper calls for better data and new methods to understand the issue.