[2]
;
Isabel Araújo
[3]
;
Rui Ferreira Jesus
[3]
;
Estela Vilhena
;
Ricardo Castro
;
Paula Lobato de Faria
[4]
;
Sónia Caridade
[1]
Braga (São José de São Lázaro), Portugal
Background: The growing prevalence of cyber interpersonal violence (CIV) among adolescents necessitates tools to assess its dimensions: victimization, perpetration, and bystander roles. This study develops and validates the “Cyber Interpersonal Violence Instrument for Adolescents” (CyIVIA). Method: CyIVIA’s development involved 253 adolescents, comprising 146 boys and 107 girls, aged between 11 and 16 years, from northern Portugal. The 40-item Likert-scale tool assesses direct (victimization and perpetration) and indirect (bystander roles) CIV. Analyses included exploratory and confirmatory factor testing for reliability and validity. Results: CyIVIA demonstrated internal consistency (α = 0.743–0.851) and a robust multidimensional structure. 56.5% reported CIV involvement, with gender differences: girls showed higher victimization, and boys, higher perpetration. The 8th grade emerged as a key intervention period. Conclusions: CyIVIA is a reliable tool for assessing CIV among adolescents. Interventions should focus on prevention, empower active bystanders, and promote safer digital environments.