Introduction: Sleep problems are common in medical students . One of the methods to improve the quality of sleep is lavender aromatherapy . The aim of this study was to determine the effect of Lavender aromatherapy on sleep quality of nursing students in Arak University of Medical Sciences .

  Methods: This is a clinical trial performed on 66 female nursing students selected through purposive sampling. Participants were randomly allocated into two groups (34 in intervention and 32 in control group). Sleep quality was assessed by Pittsburg Sleep Quality Scale. Intervention group used Lavender oil and control group used water. After intervention, sleep quality was assessed with the same questionnaire. Data was analyzed with SPSS using descriptive and inferential statistics.

  Results: The study revealed that 78% of participants did not have a good sleep quality . Results showed that the mean score of sleep quality before and after aromatherapy with lavender was significantly different in intervention group (p<0.05), but in control group the difference was not significant. Also there was no significant difference between intervention and control groups after intervention.

  Conclusions: Findings showed that despite positive effect of Lavender aromatherapy in intervention group, there was no significant difference between intervention and control groups after intervention. Further studies in this regard are recommended .