Abstract. We present a review of recent trends in cognitive robotics that deal with online learning approaches to the acquisition of knowledge, control strategies and behaviors of a cognitive robot or agent. Along this line we focus on the topics of object recognition in cognitive vision, trajectory learning and adaptive control of multi-DOF robots, task learning from demonstration, and general developmental approaches in robotics. We argue for the relevance of online learning as a key ability for future intelligent robotic systems to allow flexible and adaptive behavior within a changing and unpredictable environment. 1