Cyberchondria is a form of anxiety characterised by excessive online health research. It may lead to increased levels of psychological distress, worry, and unnecessary medical expenses. The aim of the present study was to develop a psychometrically sound measure of this dimension. A sample of undergraduate students (N = 208; 64% female) completed a pilot version of the cyberchondria severity scale (CSS) along with the short form version of the depression, anxiety and stress scale (DASS-21). Exploratory factor analysis identified a correlated five factor structure that were labelled ‘Compulsion’, ‘Distress’, ‘Excessiveness’, ‘Reassurance Seeking’ and ‘Mistrust of Medical Professional’. The CSS demonstrated good psychometric properties; the subscales had high internal consistency, along with good concurrent and convergent validity. The CSS may prove useful in a wide variety of future research activities. It may also facilitate the development and validation of interventions for cyberchondria.