Background, aim: Insomnia constitutes a common and very debilitating disorder in modern societies. A better understanding of the etiologies and risk factors, modifiable or not, of insomnia is essential for a swifter diagnosis and a more appropriate treatment, mitigating its toll on individuals and society. To this purpose, the present study assessed the prevalence of insomnia in a randomly-selected adult population and its relation with a diverse range of socio-demographic characteristics and medical conditions. Methods:A sample of 771 participants aged 24 to 89 years (mean age 58±13 years; 42.7% women) was randomly selected from the general population of Thrace, a prefecture in Northeastern Greece with special cultural considerations, using a two-stage stratified sampling scheme. The Greek version of the Athens Insomnia Scale (AIS) was utilized to evaluate the presence of insomnia. Moreover, the Berlin Questionnaire for Obstructive Sleep Apnea and the Epworth Sleepiness Scale for Excessive Daytime Sleepiness were also utilized. Results:A total of 141 study participants (18.3%) were found to suffer from insomnia. Impaired sleep maintenance was reported as the most frequent symptom (62%). The following independent statistically significant risk factors emerged (p-value <0.05): BMI ≥35 (aOR=2.91), divorced or widowed individuals (aOR=2.23), female gender (aOR=1.76), age >70 years (aOR=1.61), snoring (aOR=1.61), midday sleep (aOR=1.58) and presence of chronic disease (aOR=1.55). Conclusion:The prevalence of isomnia in Thrace aligns with similar studies conducted in Greece and internationally. A multitude of socio-demographic characteristics and diseases, especially chronic, predispose to insomnia.