Stroke is the leading cause of disability in the U.S. Many people with stroke have limited walking ability and are inactive. In this paper we describe a novel shoe based sensor, SmartShoe, and a signal processing technique to identify walking activity. The technique was validated with 6 people with walking impairment due to stroke. The results suggest that the SmartShoe is able to accurately identify walking activity. This device could be used to monitor walking activity as well as provide behavioral enhancing feedback to increase activity levels and walking ability in people with stroke for extended periods of time in the real world.