The aim of this study is to obtain a better understanding of the association between the frequency of nurses’ exposure to workplace aggression from patients and their levels of burnout. In particular, we seek to shed light on the role of the availability of follow-up counseling in organizations after critical incidents in mitigating the adverse relationships between physical and verbal aggression and nurses’ burnout. A total of 582 nurses reported how frequently they had experienced physical and verbal aggression from patients in the last 12 months and whether they had the opportunity to receive follow-up counseling in their organization. In addition, nurses rated the extent to which they experienced each of the three dimensions of burnout (i.e., emotional exhaustion, depersonalization, and personal accomplishment). The results showed that both physical and verbal aggression were substantially related to the burnout dimensions. Furthermore, we found that the availability of follow-up counseling in organizations attenuated the relationships between physical aggression and all three burnout dimensions. While we found that the availability of follow-up counseling moderated the relationship between verbal aggression depersonalization, the moderating effects were not significant for emotional exhaustion and personal accomplishment. The findings indicate that the availability of follow-up counseling might help minimize the adverse impact of exposure to aggression from patients on nurses’ mental health.