Introduction Nurse-patient communication is highly important especially when the patient is a child. One thing that has been overlooked in the nursing profession or less discussed is how to communicate with children. Design and training courses for the development of communication skills is considered as an important step in this direction. This study investigated the effect of training communication skills on children's nurses through role-playing. Materials and Methods This study is a clinical trial with pre-test and post-test which was done on 60 nurses in Dr. Sheikh Hospital in Mashhad-Iran. Nurses were randomly assigned into either intervention or control groups. Nurses' communication skills were measured using the tools of Calgary Cambridge communication skills assessment before and three weeks after the intervention. During one-day workshops, 6 hours of teaching communication skills with children were given to nurses as role playing and based on pre-prepared scenarios. Results The results showed there was no significant difference between the two groups in the mean score of nurses' verbal and non verbal communication skills before the intervention (verbal : P=0.302, non verbal : P=0.795). But after the intervention, the mean score of nurses' verbal and nonverbal communication skills in the experimental group were statistically significant and higher than those in the control group (P<0.001). Conclusion Now, due to the weakness in the relationship between nurse and child at the bedside and nurses also receive instruction on communication specific skills related to children, it seems essential that the effect of the implementation of various educational practices be examined to nurses' communication skills.