Software product line engineering focuses on proactive reuse to reduce the cost of developing families of related systems. A recently proposed method to develop software product lines is delta modeling where a set of deltas specify modifications that should be applied to a core product to achieve other products. The main advantage of this technique is its modularity and flexibility. In this paper, we propose an approach to model check delta-oriented product lines. To this end, we transform a delta model to a corresponding annotated model where an application condition is associated to each statement. An application condition specifies the set of products that a statement is included in them. We present the semantics of the resulting model in form of a featured transition system where each transition is annotated with an application condition. Featured transition systems are supported by a variability-aware model checking technique that can be used to verify the annotated model.