The study aimed to develop a short screening instrument (6 items) to assess the problematic internet use among adolescents. The Short Problematic Internet Use Test (SPIUT) has been developed based on a review of existing literature and tested using CIUS (Compulsive Internet Use Scale) as a concurrent scale. Data were collected within ESPAD-Italia (European School Survey Project on Alcohol and Other Drugs), a cross-sectional school survey conducted to monitor risk-behaviors in a representative sample of Italian students (15–19 years). The SPIUT has been validated in two steps: (a) construct validity, optimal scaling analysis, and assessment of differences in mean scores related to hours spent online (Study 1, internet users = 10,153); (b) reliability test of CIUS and concurrent validity of SPIUT (Study 2, internet users = 21,205). The SPIUT showed good psychometric properties. After Multiple Correspondence Analysis optimal weights for each item were found, improving internal consistency and reliability. Significant increase in mean score with increasing daily hours spent online was found and high correlation with the CIUS. A utilization of the SPIUT in school surveys could help us to understand the risk-profile of problematic internet users among adolescents.