Background: Although the internet has offered advantages, the side effects of Internet overuse have been emerging progressively. The aim of this work was to determine the prevalence and determinants of problematic internet use (PIU), prevalence of sleep problems and to investigate the relationship between PIU and sleep quality among secondary school pupils.

Methods: This cross-sectional study carried on 1269 male and female pupils aged 14-18 years in secondary schools in Zefta District, Gharbia Governorate. PIU was assessed by Arabic young internet addiction test (A-YIAT), and sleep quality was assessed by Pittsburgh sleep quality index (A-PSQI).

Results: About half of pupils (47.5% and 1.4%) were moderate and sever problematic internet users respectively while 51.1% were little internet addicts or no addicts. The present results showed that risk factors of PIU were young age, male sex, parents' occupation, high educational level of parents, high family income, low academic score, none educational aims of internet use, domestic internet access, increased duration of internet use, increased number of SIM card, smoking, watching TV, drinking tea or coffee, using mobile before sleep, not having hobbies, using sleep medication and no parental monitoring. The current study also revealed that 60% of pupils were poor sleepers compared to 40% were good sleepers. More than four fifths (88.9%) of sever internet addicts were poor sleepers with statistically significant relationship between PIU and sleep quality among the participants.

Conclusion: PIU is prevalent and multifaceted problem among secondary school pupils. More than half of the studied pupils had PIU and sleep problems. PIU is inversely related to sleep quality.