Background: studies evaluating screen time with a variety of lifestyle determinants have been focused, mostly on children and adolescents. To the best of our knowledge, very few studies have been conducted in adult populations, worldwide. Aim: to investigate the association between time spent on screen, for work or and entertainment, with fast food consumption, and certain lifestyle behaviors (physical activity, smoking, dietary habits), in Greek young adults. Methods: a cross-sectional, observational study with convenience sampling of 687 Greek adults, 18-30 years old, was conducted in May, 2023, using a structured web-based questionnaire. Participants were asked regarding time spent on screens (i.e., cellphone/tablet, television, computer/laptop), separately for work and entertainment, as well as various sociodemographic, clinical and lifestyle characteristics, including adherence to Mediterranean diet (through MedDietScore, ranged 0-55). Results: mean daily screen time was 5±4 hours for work and 6±3.5 hours for entertainment. Screen time for entertainment was inversely associated with a participant’s adherence to the Mediterranean diet (OR per 1 h, 0.93, 95%CI 0.89, 0.97, p=0.002). A positive association was found between fast food, sweet and salty snacks consumption with overall screen time (all p-values<0.05), while recreational screen time was inversely associated with the likelihood of a person being physically active (OR per 1 h, 0.90, 95%CI 0.85, 0.95,p=0.001). Body mass index was also positively associated with remote work screen time (rho=0.27, p=0.027). No associations were observed regarding smoking habits. Conclusion: a potential link between screen time and devaluation of the quality of life was revealed, which, in the long-term, can impact human health status.