Objectives/Introduction: High school students in their adolescence age need at least 8–9 hours of good quality sleep. Their sleeping problems are thought to be due to late melatonin secretion and bad sleep habits, especially in the urban population. The aim of this study was to assess the sleep habits and sleep quality of high school urban students. Methods: An anonymous online questioning of high school students (grades 10–12), from 7 lyceums of Chisinau and Balti, included: questions regarding sleep habits, the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS). Results: The mean age of 118 responders was 17 ± 1.1 years, male to female ratio 1:2.6. The mean time of actual sleep was 6.5 ± 0.9 hours, 41.5% (49/118) slept less than 7 hours per day, and 98.3% (116/118) went to bed after 10.00 PM. 96.6% of participants (114/118) declared the usage of the cell phone before bedtime, 66.9% (79/118) -the consumption of coffee and energizers after 5:00 PM and 45.8% (54/118) declared eating carbohydrates after 7:00 PM. The prevalence of smokers was 10.2% (12/118). The mean ESS was 6.9 ± 0.6, but in 84.7% (100/118) of participants was registered higher normal daytime sleepiness (6–10 points). The mean PSQI score was 7.2 ± 0.5, and the prevalence of ‘poor’ sleepers (PSQI score > 5) was 69.5% (82/118). Conclusions: More than a third of high school students slept less than 7 hours per day, and every second had poor sleep habits. About half of the responders waked up tired, and the majority of the students are drowsy during the day. Also, the sleep quality was assessed as bad and very bad. This condition can negatively influence cognitive performances, behaviour and life quality in high school students. An awareness program about the importance of healthy sleep and circadian rhythm should be organized for the high-school students. Disclosure: Nothing to disclose.