This paper develops an endogenous growth model to examine the interaction between trade, economic growth, and the environment. We find that whether trade enhances or retards growth depends on the relation between factor intensities of exportable, importable, and R and D and the relative abundance of the factor R and D uses more intensively. Depending on the intertemporal elasticity of substitution, the long-run rate of economic growth changes with environmental externalities. Concerns about the environment can explain a significant part of cross-country difference in growth rates. For the empirically reported range of the elasticity of intertemporal substitution, countries which care more about the environment grow faster. The effects of trade on the environment and welfare depend on the elasticities of supply for the two traded goods, the terms of trade effect on growth, and pollution intensities. The decentralized and Pareto optimal growth rates are, in general, different. The market growth rate is greater than the optimal rate the larger the degree of monopoly power in the innovation sector and the stronger the effects of environmental externalities. The policy implications of this divergence are discussed. We also consider numerical exercises to broaden the insights from the analytical results and allow for incorporating pollution abatement.