Despite the large growth on gaming behaviour research, little has been done to overcome the problem stemming from the heterogeneity of gaming addiction nomenclature and the use of non-standardised measurement tools. Following the recent inclusion of Internet Gaming Disorder [IGD] as a condition worthy of future studies in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders [DSM-5], researchers have now an opportunity to reach consensus and unification in the field. The aim of this study was to develop a new nine-item short-form scale to assess Internet Gaming Disorder (IGDS9-SF) and to further explore its psychometric properties. A sample of 1060 gamers (85.1% males, mean age 27 years) recruited via online gaming forums participated. Exploratory factor analysis [EFA], confirmatory factor analysis [CFA], analyses of the criterion-related and concurrent validity, reliability, standard error of measurement [SEM], population cross-validity, and floor and ceiling effects were performed to assess the instrument’s psychometric properties. The results from the EFA revealed a single-factor structure for IGD that was also confirmed by the CFA. The nine items of the IGDS-SF9 are valid, reliable, and proved to be highly suitable for measuring IGD. It is envisaged that the IGDS9-SF will help facilitate unified research in the field.