The purpose of this study was to examine the effect of auricular acupressure on bowel symptoms, stress, mental health, and heart rate variability in women with irritable bowel syndrome (IBS). A quasi-experimental study design with a nonequivalent control group assessed a total sample of 56 women diagnosed with IBS according to Rome III criteria. There were 29 women in the experimental group who received auricular acupressure; 27 women were in the control group. Semen sinapis albae seeds were used to administer acupressure to four auricular points: Endocrine, large intestine, lung, and Shenmen for 5 days/week for 4 weeks; the control group received no treatment. Bowel symptoms, stress, mental health, and heart rate variability were measured twice, once before and once after the intervention. Chi-square tests, t tests, and paired t tests were used for analysis. The experimental group had decreased loose stools, abdominal pain, diarrhea, abdominal discomfort, stress, and heart rate variability compared with the control group (p <.05). Auricular acupressure was effective for symptom improvement in patients with IBS.