INTRODUCTION: The study of adolescents' sleep habits is of increasing scientific interest because of the variability of sleep patterns and the frequency of sleep disorders in those of this age group. OBJECTIVE: The aim of our study was to investigate the sleep habits of adolescents living in Greece. METHODS: We analyzed responses given to preconstructed questionnaires on sleep habits and disturbances from 1331 high school students (mean age: 15 years [range: 14–18 years]). The students were attending high schools of rural, semiurban, and urban areas of Thrace, Ipirus, and Crete (all in Greece). RESULTS: The median nocturnal and total sleep duration was 7.75 hours (range: 2.5–12.3 hours) and 8.5 hours (range: 2.5–14.0 hours), respectively, and the average bedtime was 11:30 pm. Male students, older adolescents, and residents of towns were going to bed later than female students, younger adolescents, and residents of villages (P = .039, .0003, and .056, respectively). Siesta on a regular basis was reported by 43% and on an occasional basis by 46% of the students. Siesta median duration was 2 hours (range: 0.5–4.5 hours). Daytime sleepiness, difficulties in morning awakening, difficulties in falling asleep, and night awakenings were reported by 15.6%, 14%, 17.2%, and 8.11%, respectively. Students who practiced siesta reported less daytime sleepiness (P < .0001). Significant differences were observed between boys and girls regarding sleep disturbances. CONCLUSIONS: Adolescents in provincial Greece present quite a different sleep pattern compared with their northern European peers, characterized by a late bedtime and midday siesta. Similar to their peers in other countries, considerable rates of sleep disturbances were reported.