The theoretical framework for describing solvent effects on solution phase reactions is summarized. When possible, the results are related to experiments involving geometric isomerization, to photoinduced reactive processes that are initiated at the transition state, and to the bimolecular reactions between molecules that are at van der Waals separations in liquids. Key differences between solution and gas phase transition state dynamics are pointed out, and the relaxation processes that determine wavepacket propagation in the solution phase are discussed. Quantum activated rate processes are described theoretically, and some results on proton transfer are given.