Diffusion of responsibility is a phenomenon that every person experiences in their everyday life, consciously or unconsciously. Research shows that as many as 88% of participants witnessed at least once in their life a situation when an adult disciplines a child using corporal punishment, and as many as 93% of young people testify that they experienced at least once some form of physical violence by the time they reached adulthood. The aim of this quantitative research was to examine mothers about their readiness to react to witnessing violence of children with regard to the characteristics of the perpetrator, the situation and their own beliefs about corporal punishment of children. The results rejected the hypotheses that assumed that mothers would show less willingness to react to witnessed violence in the case when the perpetrator is a man and when 10 observers are present. Also, the third hypothesis, which expected a connection between beliefs about the justification of corporal punishment of children and less willingness to react to witnessed violence, was partially confirmed. Mothers who expressed greater agreement with the belief about the justification of corporal punishment expressed less willingness to inform the Center for social work and the police and shout at the perpetrator to stop the violence.