Objective: Tolerance and resilience in the face of numerous problems faced by mothers of children with attention-deficit/hyperactivity disorder (ADHD) plays a significant role in their health and that of their children. It is critical to identify training methods that can promote these abilities in mothers. The present study aimed to investigate the effect of spiritual intelligence training on the resilience of mothers of children with ADHD. Methods: In this quasi-experimental study, 30 mothers visiting private centers in Ahvaz, Iran, were selected through convenience sampling and randomly divided into experimental and control groups (n=15 each). Each group was assessed in terms of resilience on pre- and posttest and the experimental group received spiritual intelligence training. Data were analyzed using ANCOVA. Results: The results showed an increased resilience in the experimental group following training. The difference in posttest scores of resilience was significant across groups (p=0.001). Conclusion: The findings showed that spiritual intelligence training increased the scores of resiliency. Thus, spiritual intelligence training significantly improves the resilience of mothers of children with ADHD.