Background: Anxiety in patients admitted at the Intensive Care Unit (ICU) is common and usually moderate or severe. Anxiety affects endocrine and physiological responses. Objectives: This study aimed to determine the effect of aromatherapy by rose essence on anxiety and physiological indices of conscious patients admitted at ICU. Methods: In this clinical trial, 60 conscious patients admitted at ICU wards in Ali Ibn Abi Talib Hospital of Rafsanjan were selected and randomly allocated into two groups of intervention and control. In the intervention group, three drops of 10% rose essence were poured on the gauze and placed 20 cm from the patients’ nose on their shirt, and the patients inhaled it for 20 minutes three times a day. In the control group, three drops of distilled water were used likewise. Data collection tools included Spielberger State-Trait Anxiety Inventory (STAI) and the demographic questionnaire. Data were analyzed using SPSS V.18. Results: According to the results, in the intervention group, the systolic and diastolic blood pressure significantly increased (paired t-test, P < 0.05) in the second time after the intervention and significantly decreased (paired t-test, P < 0.05) in the third time. The mean oxygen saturation of arterial blood also significantly increased in the second time in this group after the intervention (paired t-test, P = 0.001). However, there was no significant difference in anxiety score before and after the intervention in each group. Conclusions: Although aromatherapy using rose essence was statistically significant on some of the physiological indices of conscious patients in ICU, these differences were not clinically significant.