In this talk, we will describe a mechanism that generates oscillations in simple stochastic models of epidemic dynamics. We will show that, first, intrinsic (demographic) stochasticity can generate large coherent fluctuations which behave as sustained oscillations and that, second, the power spectrum of these fluctuations can be calculated analytically using the system size expansion. The application of this analysis to the problem of the modeling of recurrent epidemics shows that, in systems whose sizes represent real populations, the role of stochastic effects becomes fundamental for the interpretation of historical data.