This study presents data on the effectiveness of participatory training, called 'Improvement Groups', voluntarily adopted in four nurseries in Northern Italy to prevent episodes of violence by staff toward children. The interventions provided for the representation of problematic cases, experienced by participants, relating to factors of work stress, poor collaborative practices, lack of protection of children, and poor quality of service provided. The participants (n = 47) were then involved in interactive training that allowed them to focus on: analysis of causes; risk assessment; and improvement actions. Effectiveness outcomes for knowledge, attitudes, safety climate, and health were assessed pre- and post-training. The data collected show that the Improvement Groups always increased the level of knowledge and safety climate. The results suggest that these interventions should be extended to other similar settings, in order to promote peer-education, appreciation, and effectiveness in generating consensus through the comparison of problematic cases that actually occur.