BACKGROUND: Existing instruments for measuring problematic computer and console gaming and internet use are often lengthy and often based on a pathological perspective. The objective was to develop and present a new and short non-clinical measurement tool for perceived problems related to computer use and gaming among adolescents and to study the association between screen time and perceived problems. METHODS: Cross-sectional school-survey of 11-, 13-, and 15-year old students in thirteen schools in the City of Aarhus, Denmark, participation rate 89%, n=2100. The main exposure was time spend on weekdays on computer- and console-gaming and internet use for communication and surfing. The outcome measures were three indexes on perceived problems related to computer and console gaming and internet use. RESULTS: The three new indexes showed high face validity and acceptable internal consistency. Most schoolchildren with high screen time did not experience problems related to computer use. Still, there was a strong and graded association between time use and perceived problems related to computer gaming, console gaming (only boys) and internet use, odds ratios ranging from 6.90 to 10.23. CONCLUSION: The three new measures of perceived problems related to computer and console gaming and internet use among adolescents are appropriate, reliable and valid for use in non-clinical surveys about young people's everyday life and behaviour. These new measures do not assess Internet Gaming Disorder as it is listed in the DSM and therefore has no parity with DSM criteria. We found an increasing risk of perceived problems with increasing time spent with gaming and internet use. Nevertheless, most schoolchildren who spent much time with gaming and internet use did not experience problems.