Harmonic distortion on voltages and currents increases with the increased penetration of Plug-in Electric Vehicle (PEV) loads in distribution systems. Wind Generators (WGs), which are source of harmonic currents, have some common harmonic profiles with PEVs. Thus, WGs can be utilized to subside the effect of PEVs on harmonic distortion. This paper studies the impact of PEVs on harmonic distortions and integration of WGs to reduce it. A harmonic decoupled power flow model is developed, where PEVs and WGs are represented by harmonic current loads and sources, respectively. The developed model is first used to solve harmonic power flow on IEEE 34-node distribution test feeder with low, moderate, and high penetrations of PEVs, then its impact on total harmonic distortions (THDs) is studied. Next, optimal size of WGs are calculated using Genetic Algorithm in the test feeder to reduce voltage and current THDs below the IEEE recommended values.