Non-motor symptoms inevitably worsen as Parkinson’s disease (PD) progresses, and in advanced stages of the disease can contribute to severe disability and reduced quality of life. Non-motor symptoms often go unrecognised, however; clinicians may be ill equipped to diagnose them, and they may be underreported by patients due to a lack of association with PD or through embarrassment. Clinical evaluation is therefore required in order to develop a comprehensive treatment strategy, especially since the emergence of some non-motor symptoms may represent the optimum time for therapeutic intervention. A number of tools are currently available for the assessment of non-motor symptoms, and increasing numbers are being developed and validated for the specific monitoring of non-motor symptoms in PD patients.