OBJECTIVE: To present the rationale, design, and methodology of the Fibroid Interventions: Reducing Symptoms Today and Tomorrow (FIRSTT) study. DESIGN: Randomized clinical trial. SETTING: Two academic medical centers. PATIENT(S): Premenopausal women with symptomatic uterine fibroids. INTERVENTION(S): Participants are randomized to two U.S. Food and Drug Administration-approved minimally invasive treatments for uterine leiomyomas: uterine artery embolization and magnetic resonance-guided focused ultrasound. MAIN OUTCOME MEASURE(S): The primary endpoint is defined as the need for an additional intervention for fibroid symptoms following treatment. Secondary outcomes consist of group differences in symptom alleviation, recovery trajectory, health-related quality of life, impairment of ovarian reserve, treatment complications, and the economic impact of these issues. RESULT(S): The trial is currently in the phase of active recruitment. CONCLUSION(S): This randomized clinical trial will provide important evidence-based information for patients and health care providers regarding optimal minimally invasive treatment approach for women with symptomatic uterine leiomyomas. CLINICAL TRIAL REGISTRATION: NCT00995878.