Clinical evaluation of motor dysfunction is crucial to make a correct diagnosis. The gold standard is clinical evaluation by a movement disorder specialist, relying on subjective measures and patient report. Regular clinical assessments are needed to provide long-term measures that monitor motor progression over time and therapy response, not only in clinical settings but also during daily activities at home. Wearable sensors have been developed to assess objective and quantifiable measures of motor dysfunction. Such sensors are small, light, cheap and portable, containing built-in accelerometers and gyroscopes and data storage. These new technologies are revolutionizing the field of movement disorders to improve clinical diagnosis and evaluation, treatment monitoring at home, and progression of symptoms over time. They are also of interest for adaptive therapy options, e.g. closed-loop deep brain stimulation, and are successful in quantifying and measuring tremor, showing promise in assessing bradykinesia, dyskinesia, gait impairments and prediction of therapy response. Despite device development, there is no validated clinical application yet; further research is needed.