<p>The objective of this work is to know which sociodemographic and psychological characteristics of the vulnerable Dominican student function as risk and protective factors for bullying. There were 531 secondary school students from the Dominican Republic. The results showed that, among the socio-demographic variables, only first grade of secondary school and male gender were linked to bullying, while psychological variables showed significant and positive relationships with physical and verbal aggression, negative suicidal ideation, and emotional instability; and negative with prosocial behaviour, positive suicidal ideation, and self-esteem. These results provide relevant information to prevent and fight against bullying, taking into account the control factors that may be of risk, such as physical and verbal aggression or emotional instability, and promoting those that may function as protective, such as prosocial behaviour or self-esteem.</p>