This study aimed to develop an internet addiction scale for adolescents according to DSM V diagnostic criteria of internet gaming disorder. The study was conducted on 656 adolescents whose ages varied between 10 and 18 years. A pilot form was applied on 42 individuals; 349 individuals were subjected to an exploratory factor analysis, 215 individuals were subjected to a confirmatory factor analysis, and the test-retest study was performed with 50 individuals. The content validity was achieved with expert opinions. The factor analysis confirmed the validity of the nine-item and single-factor construct. The single-factor construct explains approximately 40% (39.901%) of the scale’s variance. Scale’s KMO (Kaiser-Meyer-Olkin) value was found to be .820, and Bartlett’s Test for Sphericity is χ²= 850,521, p=.000. Common factor variances of the scale items were found to be ranging from .300 to .500, and item factor loadings from .548 to .707. The CFA achieved fit indexes (X2 /df =1.984, RMR=.028, GFI=.95, AGFI=.91, CFI=.93, RMSEA= .068) which are adequate for the confirmation of the model. Item-total correlation of the scale is between .427 and .587; the correlation coefficient of the test-retest performed at one-month interval is r= .72; Cronbach’s Alpha internal consistency coefficient is .81, and the t-test results for upper and lower 27% groups are significant. These results indicate that the scale is a reliable instrument. Addressing the results in overall, one can argue that the developed Internet Addiction Scale for Adolescents is a reliable and valid instrument.