© 2021Background: Patients undergoing haemodialysis suffer from anxiety and pain due to the insertion of haemodialysis needles, estimated totally 320 times per year. Aims: This randomized controlled trial was conducted in order to determine the effect of lavender aromatherapy, performed through inhalation for five minutes three times a week, on pain and anxiety experienced by patients undergoing haemodialysis after needle insertion into a fistula. Design: Patient information form, Numeric Rating Scale (NRS) and State-Trait Anxiety Inventory (STAI) were applied to patients in the intervention group at the first follow up (the first interview before aromatherapy administration). Settings: The researcher completed the data collection forms by conducting face-to-face interview with the patients and applied lavender oil to all the patients in the intervention group at the last hour of every dialysis session. Participants/Subjects: Totally three sessions were carried out as three times for one week in accordance with protocol of aromatherapy inhalation. Methods: It took 5 minutes to complete each session. Olive oil was applied to the placebo group since it has no therapeutic value. At the end of the application, NRS and STAI were applied to the patients again. Results: The use of lavander aromatherapy significantly reduced the scores of arteriovenous fistula (AVF) puncture-related pain, which was 6.24±1.24 in the first session, to 3.56±1.28 in the second session (p=0.002). It was found that scores of STAI obtained at the first follow-up) were higher in the intervention group than the placebo group but the difference between them was not statistically significant (p>0.05). The STAI mean scores of the patients in the intervention group after aromatherapy were 39.12±6.71 in the state anxiety subscale and30.04±1.39 in the trait anxiety subscale. All subscale scores of STAI decreased significantly in the intervention group in the second follow-up compared to the first follow-up (p<0.05). Conclusions: Lavender inhalation could be used as a safe, simple, and low-cost method in nursing care if it is proved to be effective in reducing anxiety and relieving pain after needle insertion into a fistula in patients undergoing haemodialysis.