One of the open challenges in Human-Robot collaborative tasks is to provide a simple way for humans to understand robotic systems’ plans and actions and to interact with them in the most natural way. Towards the direction of a natural interaction between human and robots, we propose a simple and intuitive interface exploiting the emergent Augmented Reality (AR) technology. This interface aims not only to enhance human awareness of the robot status and planned actions during collaborative tasks, but also to improve the quality of the work. The presented interface enables the human operators to interact with the system sending commands (gesture or vocal) and receive instant feedbacks (holograms and sound) through an AR device, enabling an intuitive way to coordinate human and robot actions. The interface validation is performed through two industrial scenario experiments, i.e., a collaborative assembly of a metallic structure and a collaborative polishing. The experimental results showed that the presented AR interface could be exploited to improve human operators’ performance while performing an industrial task. At the same time the usage is also perceived as beneficial by ten subjects that tested the interface in the experiments.