The purpose of the study was to determine the effects of screen time on the physiological variables of Nigeria Adolescents. A quasi-experimental research design was adopted in carrying out the study. The physical characteristics of blood pressure, body composition, muscular strength and endurance of children were measured after parental consent has been obtained. The sample for this study comprised a total of sixty (60) participants selected through a convenient random sampling technique. Twenty (20) students were selected from three schools. The procedure and methods used for the study was approved by the Departmental Postgraduate Committee before carrying out the experiment. International Council for Health, Physical Education, Recreation, Sport and Dance (ICHPER.SD) Standardized test and instruments were used in data collection during the study. The instruments were calibrated. Data from the experiment conducted was analyzed using the descriptive statistics of mean and standard deviation with graphical illustration while the hypotheses were tested using the inferential statistics of independent sample t-test at a 0.05 level of significance. Findings indicated that there was a significant relationship between high and low screen time on the systolic blood pressure, diastolic blood pressure, body mass index (BMI), waist to hip ratio (WHR), muscular strength and muscular endurance of participants. The study recommends the promotion of healthy 7 and active lifestyles through the support of parents and teachers.