Objective: This study aimed to determine impact of eHealth literacy on health promotion activities and preventive health practice among adolescents. Methods: This cross-sectional study was conducted between March and May 2022 with 706 adolescents in Çorum, Turkey. A face to face questionnaire form including socio demographic characteristics, preventive health practices, eHealth Literacy scale and Adolescent Health Promotion Scale were used. The data of the research were analyzed with the SPSS 22.0 program. Percentage, mean, Pearson Correlation analysis and multiple regression analysis were used in the analyzes. The p<0.05 value was considered statistically significant in the evaluations. Results: In the study, 55.8% were female and the mean age of the whole group was 16.09±2.63 years. The mean score of eHealth Literacy scale was 29.40±6.29. The mean of the total scores obtained from the Adolescent Health Promotion Scale was 137.97±21.87. Among the adolescents 96.0% didn’t use alcohol and 81% didn’t smoke. The rate of annual weight measure was 68.8%. Measurements of annual blood pressure, annual blood iron, annual cholesterol, annual dental examination and regular exercise rate were below 50%. There was a significant positive correlation between eHealth literacy and the Adolescent Health Promotion Scale (p<0.001). Multiple linear regression analysis was performed to predict eHealth literacy using the variables of Adolescent Health Promotion and preventive health practices. eHealth literacy was positively and significantly predicts health promotion behaviors (β= 0.27, t (695)= 7.54, p<0.001). eHealth literacy increased annual weight measurement by more than 0.13 (β=0.13), the annual blood iron measurement by more than 0.16 (β=0.16), annual dental examination by more than 0.11 (β=0.11). Conclusions: Adolescents ehealth literacy was high and effected via health promotion activities and preventive health practices. Developing eHealth litracy interventions will be important for environments with a high concentration of adolescents (schools, courses). Also, primary health care services should be entegrated with school environment.