Aşut Ö, Abuduxike G, Acar-Vaizoğlu S, Cali S. Relationships between screen time, internet addiction and other lifestyle behaviors with obesity among secondary school students in the Turkish Republic of Northern Cyprus. Turk J Pediatr 2019; 61: 568-579. Obesity among children and adolescents is one of the critical public health problems worldwide, and the prevalence of obesity has been increasing rapidly over decades. We examined the associations between screen time, internet addiction and other life style behaviors with obesity among high school students in Near East College in Northern Cyprus. A cross-sectional study was conducted among 469 secondary school students with mean age 11.95 ±0.81 years. A self-administrated questionnaire was applied to assess screen time and life style behaviors. The Turkish adapted version of the short-form of internet addiction test was used to assess internet addiction problems. Height and weight were measured objectively to calculate body mass Index (BMI) and classify based on the BMI percentiles for sex and age. Descriptive analysis, Chi-Square test and multivariate regression analysis were performed, and the p- value < 0.05 was accepted as significant. Of all participants, 17.2% were overweight and obese, and 18.1% had internet addiction, while 40.7% of them reported to have screen time of more than two hours a day. After adjusting the analysis for age and sex, eating snacks while watching TV (OR,3.04; 95% CI, 1.28-7.21), self- perceived body weight (OR, 24.9; 95% CI, 9.64-64.25) and having a play station in the room (OR,4.6; 95% CI, 1.85 - 11.42) were significantly associated with obesity. Screen time (OR,4.68; 95% CI, 2.61-8.38; p=0.000) and having a computer in the bedroom (OR,1.7;95% CI, 1.01- 2.87; p=0.046) were significantly associated with internet addiction, whereas parent`s complaint about lengthy technology use (OR,0.23; 95% CI, 0.11-0.46; p=0.000) was found to be a protective factor against internet addiction. The findings highlighted the significance of a family - school based integrated approach, which should be implemented to tackle obesity problem to improve the quality of life of children and adolescents.