Pain is one of the common problems in burn patients. Inhalation aromatherapy is one of the nurses' methods for pain management. However, there is not much information available about the effect of these methods on pain in burn patients. This study aimed to evaluate the effect of inhalation aromatherapy with Lavender essence on the pain intensity in burn patients. Methods: The present study was a single-blind, three-group clinical trial. The research population consisted of patients with burns in one of Hamadan hospitals. One hundred and twenty patients were selected using convenience sampling and randomly assigned into three groups of lavender, placebo and control groups. The intervention included inhalation of 10 drops of lavender extract in the examiation group, 10 drops of distilled water in the placebo group, for one hour before wound dressing, and routine care in the control group. Pain in patients was evaluated before, immediately after intervention (before dressing), and after dressing using a visual analogue scale. The data were analyzed using SPSS 21 and one-way and repeated measures ANOVA with significant level of P<0.05. Results: Demographic variables were similar in all three groups. There was a significant difference between the mean pain intensity in the groups after intervention (P<0.05), which was significant between the lavender group with placebo and control group (P<0.05). There was not a statistically significant difference between the control and placebo groups (P=0/443). Conclusion: The use of lavender aroma can reduce short-term pain of burn patients. Therefore, the use of lavender aroma is recommended in short term pain by medical staff and nurses.