Purpose: This study was an experimental study to compare the inhalation effects of aroma essential oil on the quality of sleep (QOS) for shift nurses after working nights. Methods: The participants were 60 healthy adults who didn’t have any disease. As an experimental treatment, the participants in the experimental group were asked to inhale essential oil for 3 minutes at a distance of approximately 10 cm fromt heir nose and then they were asked to sleep with the aroma stone beside their head (within a 30 cm distance). QOS were measured four times on Pretest,Day 1, Day 2, and Day 3 after they slept. To measure QOS, Perceived QOS (Numeric Rating Scale), the Verran qqqamp; Synder Halpern (VSH) Sleep Scale were used, and number of awakenings (NoA) was measured by Actigraph. Results: There were no significant differences in the homogeneity tests for general characteristics and dependent variables prior to the experiments, except for VSH of subjective sleep quality. Also, there was no significant interaction between group and time. The VSH of the experimental group was higher than the control group (F=6.39, p =.002). The NoA between the experimental group and the control group was significantly different after experimental treatment 3rd day (F=13.35, p =.001). Conclusion: The findings show that the inhalation of aroma essential oil had effects to increase the quality of sleep. Therefore, the inhalation of aroma essential oil could be applied to general nursing interventions to improve the quality of sleep .