The purpose of this paper is to examine the relationship between carbon dioxide (CO2) emissions from oil and GDP, using panel data from 1971 to 2007 of 98 countries. Previous studies have discussed the environmental Kuznets curve (EKC) hypothesis, but little attention has been paid to the existence of a nonlinear relationship between these two variables. We argue that there exists a threshold effect between the two variables: different levels of economic growth bear different impacts on oil CO2 emissions. Our empirical results do not support the EKC hypothesis. Additionally, the results of short-term analyses of static and dynamic panel threshold estimations suggest the efficacy of a double-threshold (three-regime) model. In the low economic growth regime, economic growth negatively affects oil CO2 emissions growth; in the medium economic growth regime, however, economic growth positively impacts oil CO2 emissions growth; and in the high economic growth regime, the impact of economic growth is insignificant.