This is usually made on the basis of a history of the symptoms or as an incidental finding at routine vaginal examination at the time of a cervical smear test. In women being investigated for infertility, fibroids are often found at a routine ultrasound scan. Currently ultrasonography is the commonest method of confirming the diagnosis of leiomyomas, although MRI (magnetic resonance imaging) and CT (computed tomography) have also been used. Although expensive for routine use, MRI may prove to be the most useful method because it can often distinguish leiomyomas from other intramural lesions.

More invasive procedures including Hystero-salpingography, Sonohysterography (XRay pictures and ultrasound pictures respectively to visualise the uterine cavity after a specific dye has been injected into the uterus) and Hysteroscopy may be used in the evaluation of the uterus. Hysteroscopy allows direct visualisation of the uterine cavity through a telescope introduced into the uterine cavity through the cervix (neck of the womb). Laparoscopy on the other hand allows direct visualisation of the outside of the womb by introducing a telescope into the abdominal cavity.