To know the diagnostic precision of ultrasound in the detection of deep infiltrative endometriosis. This is a retrospective study of diagnostic accuracy of prospectively collected data from patients with pelvic pain who underwent transvaginal ultrasound before surgery, performed by gynecologists who are experts in ultrasound. This study was conducted in a tertiary-level university hospital. Data was collected between January 2018 and January 2021. Deep infiltrative endometriosis was defined as those patients who presented lesions > 5 mm in deep, involving at least one of: pelvic anterior or posterior spaces (nodules or obliteration), uterine torus, uterosacral ligaments or intestinal involvement (anterior wall). Laparoscopy exploration was the gold standard used in this study. Predictive values of sensitivity, specificity, positive (PPV), negative (NPV) predictive values and likelihood ratio (LR) were calculated. A total of 290 patients underwent ultrasound at our institution. 214 women were excluded because they did not have adequate preparation for ultrasound mapping of endometriosis. Thus, a total of 76 patients were finally included, of which 28 had confirmed deep infiltrative endometriosis. Ultrasound sensitivity, specificity, PPV, NPV, positive and negative LR values were 29%, 94%, 72%, 69%, 4,5% and 0,7% respectively. The low detection rate was dependent on uterosacral ligaments involvement and posterior cul-de-sac obliteration, these two affecting the sensitivity. Ultrasound mapping for endometriosis at our centre allows us to accurately exclude healthy patients. A prospective study is necessary to allow the implementation of strategies to improve sensitivity.