Transabdominal ultrasound has a lower diagnostic yield in acute appendicitis than computed tomography (CT) scanning. The addition of transvaginal sonography in women with suspected appendicitis has shown improvement in the efficacy of diagnosis, potentially providing the option of selective CT use and reducing overall investigative cost and surgical delay. Two hundred ninety-two women who underwent combined transabdominal and transvaginal ultrasound for suspected acute appendicitis were evaluated. Patients were divided into two groups; Group 1 including patients with a positive sonographic diagnosis of appendicitis who underwent operation and Group 2 including patients with a negative sonographic diagnosis. Of the 157 women in Group 1, the diagnosis of appendicitis was histologically confirmed in 144 patients with five cases having a normal appendix in whom eight other pathologies were found. Of the 135 women with negative ultrasound examinations, 14 underwent surgery in which four cases of appendicitis were found. The sensitivity of the combined approach was 97.3 per cent, the specificity 91 per cent, the positive predictive value 91.7 per cent, and the negative predictive value 97 per cent. Combined ultrasound has a high predictive value for the diagnosis of appendicitis and may assist in reduction of the use of CT scanning for diagnosis and in the negative appendectomy rate.