SYNOPSIS. Studies of life history evolution, as well as much of life history theory, have typically focused on “hard” components of life histories; phenotypic characteristics that can be readily observed, quantified, and ultimately, connected rather directly to fitness. Typical of these are propagule size, propagule number, and age and size at maturity. What is largely missing from the study of life history evolution is consideration of the role of behavior, principally female oviposition site choice, in the evolution of life histories. For oviparous organisms, natural selection cannot produce locally optimized “hard” components of life history phenotypes without a consistent environmental context (whether invariant orvariable); in a variable environment, that consistent environmental context can be most effectively provided by interactive oviposition site choice. I present a model of selection on oviposition site choice in the context of the evolution of “hard” components of life history phenotypes, along with some experimental data illustrating oviposition site choice in response to predators. The model and data are then related to the overall question of the role of oviposition site choice in life history evolution. The conclusion is that oviposition site choice must be under equally strong selection with egg size, egg number and the other hard components of life histories in order to generate and optimize locally adapted or ecologically specialized life history phenotypes, and must therefore, play a significant role in the evolution of life histories.