The aim of the present study was to examine the muscle activity of patients with stroke during robotic walking. In the robotic walking condition (RWC), subjects (n=10) walked in a robotic walking device with minimal support and a walking speed of 2.2 km/h. In the overground walking condition (OWC), subjects walked without any assistance on their preferred walking speed. The results showed significant differences between conditions in individual phases of the gait cycle. Thereby, a significant lower EMG amplitude was found in the RWC compared to the OWC. Furthermore, significant interaction effects were found indicating a higher activity of the paretic semitendinosus and gastrocnemius muscle during the RWC compared to the OWC, supporting the use of robot treadmill training after stroke.