Adolescents' use of the Internet is becoming a matter of great concern for different sectors of society. The psychological and behavioural consequences of problematic Internet use in young people demands quick and effective answers. One of the major challenges in this context is the development of empirically validated tools, which would facilitate early detection and screening for potential risk cases. This is precisely the aim of this paper. Based on a sample of 1,709 secondary-school students from Galicia (a region in northern Spain) aged 11 to 17 (M = 13.74, SD = 1.43), the analysis carried out permitted us to present a brief and simple tool (with just 11 items). It has substantial theoretical support, since both the existing background information and the views of experts from the academic and professional spheres were taken into account in the course of its development. The scale is adapted to the Spanish cultural context and to the language of young people. It has satisfactory psychometric properties in terms of reliability of the scores (α = .82), evidence of its internal structure (tested via a Confirmatory Factorial Analysis), sensitivity (81%), and specificity (82.6%). Moreover, its use enables the gradation of adolescents on a risk or problematic Internet use continuum. In our view, all of this lends it enormous applied potential in both the educational and clinical contexts.