[Purpose] This study compared the upper extremity recovery of stroke patients with the amount of their upper extremity use in real life as measured by accelerometers. [Subjects] Forty inpatients who had had a stroke were recruited. [Methods] The subjects were divided into two groups by the Fugl-Meyer Assessment of Motor Function (FMA) score, a moderately recovered group and a well recovered group. The amount of upper extremity physical activity and its ratio in daily time periods were analyzed for the affected and unaffected sides. [Results] The well recovered group showed significantly higher affected arm use and use ratio than the moderately recovered group in all time periods. [Conclusion] The upper extremity recovery level of the affected side is similar to the physical activity level according to the amount of upper extremity physical activity in actual life measured with an accelerometer. Overuse of the normal side regardless of the recovery level of upper extremity proves the International Classification of Functioning (ICF) concept of differentiating between capacity and performance, and rehabilitation treatments should focus on improving performance.