Background: The recurrent arteriovenous fistula (AVF) intervention in the treatment of hemodialysis induces pain in patients. Lavender oil has analgesic, antimicrobial, and calming effects. This oil is widely used in patients to reduce anxiety and stress associated with pain caused by analgesics. Method: The present study is a randomized controlled and experimental clinical trial in which patients (n = 90) who underwent hemodialysis with AVFs were randomly divided into three groups. The intensity of pain was measured in all patients at three different stages during the insertion of arterial needles for hemodialysis: (1) The topical application of 100% lavender essential oil, (2) the inhaler application of 100% lavender essential oil, and (3) no intervention. The placebo (water) was applied to groups 1 and 2. Results: Our findings revealed that the mean pre-application pain scores in hemodialysis patients were 57.58 +/- 20.28 in the working group, 48.53 +/- 20.23 in the control group, 19.49 +/- 15.66 in the post-application group, and 45.33 +/- 25.52 in the control group (p < 0.005). The average pain scores after the application of lavender oil were 22.66 +/- 15.35 in the inhaler lavender group, 16.33 +/- 15.97 in the topical lavender group, and 45.33 +/- 25.52 in the control group. Conclusions: After inhaler and topical application of lavender oil, a significant decrease in the severity of pain was recorded for patients at the time of arterial insertion of needles.