The authors study three predator-prey systems with delay and prey harvesting. In the first model, a time delay appears in the prey specific growth term, in the second model, there is a delay in the predator response, while the third one is the well-known Wangersky-Cunningham model. The authors are interested in studying the combined effects of the harvesting rate and the time delay on the dynamics of the generalized Gause-type predator-prey models and the Wangersky-Cunningham model. It is shown that in these models the time delay can cause a stable equilibrium to become unstable and even a switching of stabilities, while the harvesting rate has a stabilizing effect on the equilibrium if it is under the critical harvesting level. Some numerical simulations are given.