Introduction: Reflection is formed through deep reflection on the event or a certain clinical position. The aim of this study was to determine the effect of reflection on nurse-patient communication skills of nurses working in emergency departments. Methods: This interventional study was conducted on intervention and control groups and with a pretest-posttest design. 142 nurses working in the emergency departments of hospitals affiliated to Golestan University of Medical Sciences were enrolled in the study in 2015, and randomly divided into two groups. During eight weeks of the study, the intervention group was asked to write their clinical experiences with regard to communication issues with their patients. Before the intervention, the communication skills of both groups were compared using a questionnaire. Data analysis was performed, using independent t-test, paired t-test, Mann-Whitney and Wilcoxon tests. Results: Of the 142 nurses, 122 nurses had full participation. In the intervention group the mean scores of verbal communication skills, non-verbal communication skills, general communication skills and communication skills based on patient safety were statistically significant, but there was no significant difference in the control group. Conclusion: The results showed that eight weeks of reflection by nurses is an effective intervention in dimensions of communication skills. We therefore suggest that a reflective writing be encouraged as a vital tool for improving communication competency among emergency department nurses.