This study presents an analysis of the loads on offshore Horizontal Axis Wind Turbines (HAWTs). The aerodynamic loads are estimated using the Blade Element-Momentum (BEM) theory, including the effects of dynamic inflow and dynamic stall. The wave loads are calculated using Morison's equation. Models are proposed to account for the effects of aerodynamic damping on the fatigue loading on the tower during its working lifetime. Load analysis of a 5 MW offshore HAWT is carried out and the influence of aerodynamic damping on the fatigue load is investigated.