Recent experiments have shown the near possibility to use the brain electrical activity to directly control the movement of robotics or prosthetic devices. In this paper we report results with a portable non-invasive brain-computer interface that makes possible the continuous control of a mobile robot in a house-like environment. The interface uses 8 surface electrodes to measure electroencephalogram (EEG) signals from which a statistical classifier recognizes 3 different mental states. Until now, brain-actuated control of robots has relied on invasive approaches-requiring surgical implantation of electrodes-since EEG-based systems have been considered too slow for controlling rapid and complex sequences of movements. Here we show that, after a few days of training, two human subjects successfully moved a robot between several rooms by mental control only. Furthermore, mental control was only marginally worse than manual control on the same task.