The strong growth within the wind technology market, underpinned by policy goals around the world, has highlighted the demand for advanced engineering analysis to improve wind turbine (WT) design, both in terms of reliability and design of larger turbines. This paper presents a review of the latest research that has been carried out in modeling and analysis of load transmission in WT drive train systems and their components. Common failure roots are elaborated, and probable hypotheses are presented. A modeling approach is derived by classification into engineering, mathematical and computational models with a focus on gearbox modeling efforts. Precise understanding of drive train system dynamics and load transmission is necessary for a cost efficient and robust system design to enhance reliability and reduce the maintenance costs. Design optimization of WTs and their subsystems will make future WTs more attractive compared with fossil and nuclear power plants, and it is therefore an important issue for a more sustainable environment. Copyright © 2014 John Wiley & Sons, Ltd.