BackgroundDuring urodynamic testing (UT), patients may experience emotions such as embarrassment, discomfort, irritability, and tension, which can cause anxiety. Aromatherapy is a complementary and alternative treatment that may be employed in clinical settings to alleviate patients' anxiety before invasive procedures.ObjectivesThe aim of this study was to determine the effect of aromatherapy on patients' anxiety and cortisol levels during UT.Materials and MethodsThe sample of this single‐center, prospective, two‐armed, randomized controlled clinical study consisted of 98 patients undergoing UT. Patients were randomly assigned to the intervention group (n = 49) and the control group (n = 49). The anxiety level was assessed using the state‐trait anxiety inventory (STAI), and measured with physiological responses to anxiety, such as changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO2), and cortisol levels, pre and post‐UT. Aromatherapy was applied to the intervention group starting 5 min before UT and continuing throughout the testing. The control group received routine treatment and care. Data were analyzed using Pearson's χ2, dependent samples t‐tests, and independent samples t‐tests.ResultsIn the study, post‐UT anxiety in the intervention group was significantly lower than in the control group (p < 0.001), while SpO2 was higher (p = 0.021). In the study group, post‐UT anxiety (p < 0.001), HR (p = 0.000), and cortisol levels (p = 0.005) decreased compared to pre‐UT, whereas in the control group, anxiety (p < 0.001) and HR (p = 0.000) decreased, and SBP (p = 0.010) and RR (p = 0.004) increased.ConclusionsAromatherapy during UT positively influenced both the psychological and physiological responses to anxiety.