ENResearchers state that around 80-90% of adolescents share photos on social networking sites (SNS) (Anderson & Jiang, 2018), which may have positive and negative consequences on adolescents’ health. However, it is still unclear why adolescents engage in such kind of behaviour. Thus, the aim of this study is to find out if the Prototype Willingness Model (PWM) can explain adolescents’ risky photo disclosure on SNS. To reach this aim, a survey study was conducted among a sample of adolescents (N = 586; Mage = 14.65, SDage = 1.36; 56.9% female). Students were asked to fill in hard copy questionnaires, assessing the factors of reasoned (intention) and reactive (willingness) pathways of the PWM and risky photo disclosure on SNS. In order to test adolescents’ intention and willingness of risky photo disclosure on SNS, structural equation modelling (SEM) analysis was performed using Mplus. The results of the hypothesized model showed acceptable model fit: χ² = 3950.467, p <.001; RMSEA = .064, 90% CI [.062, .067], CFI = .935, TLI = .931. According to the results, we can state that adolescents’ risky photo disclosure on SNS is better explained by the factors of the reasoned pathway (intention) than the reactive pathway (willingness). Keywords: Prototype willingness model; risky behaviour online; photo disclosure; adolescents. [From the publication]