The creation of environmental clubs is a prominent policy proposal for addressing global environmental problems. By generating exclusive “club goods” for their members, environmental clubs provide an incentive to join them and accept their environmental obligations. Yet, the existing literature often considers intergovernmental environmental clubs as a promising theoretical idea that has still to be put into practice. This paper asks whether, in fact, the numerous International Environmental Agreements (IEAs) containing trade-related provisions provide club goods to their parties. This is the first study to investigate the effect of these provisions on trade flows among parties to an IEA compared to flows among non-parties. Making use of a novel dataset on the trade provisions of IEAs and a panel of worldwide bilateral trade flows, it finds that de facto environmental clubs are more prevalent than previously thought. The positive effect of certain trade provisions in an IEA can turn the trade-decreasing effect of the agreement into an overall trade-increasing effect. The paper also identifies specific trade provisions that show particular potential to contribute to the creation of a club good for the parties to the IEA. Studying the actual effects of IEA trade provisions is an important step in assessing the possibility of generating additional environmental clubs through trade incentives.