The wind power industry has experienced rapid growth over the past few decades, but the operation and maintenance costs have become huge challenges to achieve better economic returns and enhance the market competitiveness. In this paper, an opportunistic maintenance strategy for wind turbines considering stochastic weather conditions and spare parts management is proposed. The Markov chain model is adopted to generate wind speed time series and obtain the maintenance wait time owing to weather restrictions. The opportunistic maintenance threshold is a dynamic value related to the wind speed to reduce power generation losses. Moreover, the (s, S) inventory policy, with the reorder stock level s and maximum stock level S, is employed. Numerical examples are used to illustrate the economic advantages of the proposed strategy. Compared with a static opportunistic maintenance strategy and a strategy not considering opportunistic maintenance, the life cycle operation and maintenance cost for the proposed dynamic opportunistic maintenance strategy shows a decline of 10.927% and 18.304%, respectively. The optimal maintenance and inventory strategy is obtained with the decision variables of opportunistic maintenance reliability threshold and reorder stock level, and the effects of various applied parameters are described. (C) 2018 Elsevier Ltd. All rights reserved.