A growing body of literature on the willingness of victims to report crimes focuses on the context in which crimes occur. Recently, a socio-ecological model has been developed from which hypotheses on the effects of social context on reporting can be derived. This study tests these hypotheses using a vignette experiment, in which 499 juveniles read a description of a violent incident and answered questions on their willingness to report to the police or to an employee of the organization they belong to (here, their school). The effects of three factors were studied: the location of the crime, the extent to which victim and offender knew each other, and whether or not the offender was part of the same organization as the victim. Results show that the willingness to contact the police is lower when the incident takes place within the organization (cf. in the public domain) and when the offender is well known (cf. vaguely known), and that there is an additional negative effect when the incident takes place within the organization and the offender also belongs to the organization. The willingness to contact an employee is higher when the offender belongs to the organization and when the incident takes place within the organization. Implications of these findings and the advantages and limitations of the vignette approach are discussed.