CONTEXT: Interest in the use of alternative therapies to reduce anxiety in patients undergoing medical interventions is increasing. We sought to assess the effectiveness of aromatherapy involving essential oils in reducing preoperative anxiety in women undergoing abortions. SETTING: An urban, free-standing abortion clinic in Vancouver, BC. PATIENTS: 66 women waiting for surgical abortions. DESIGN: A double blind, randomized trial. INTERVENTION: Ten minutes spent sniffing a numbered container with either a mixture of the essential oils vetivert, bergamot, and geranium (treatment arm) or a hair conditioner (placebo). OUTCOME MEASURES: Anxiety was measured before and after the intervention by using a verbal anxiety scale from 0 to 10. RESULTS: The anxiety score was reduced by 1.0 point (5.0 to 4.0) in the aromatherapy group and by 1.1 points (6.1 to 5.0) in the placebo group (P = 0.71). The 95% CI on the 0.1 greater decrease in anxiety for the placebo group extends from 0.55 less (favors aromatherapy) to 0.75 greater (favors placebo). CONCLUSION: Aromatherapy involving essential oils is no more effective than having patients sniff other pleasant odors in reducing preprocedure anxiety.