Summary: In this retrospective case control investigation, 51 pregnant patients who were diagnosed by ultrasound with uterine myomas were compared to 102 randomly selected control patients to determine if the ultrasound diagnosis of one or more leiomyoma is associated with increased untoward pregnancy outcomes compared to controls. Women with uterine myomas were older (p = 0.001), more likely to be African American (p = 0.001), and undergo Caesarean delivery (p = 0.03) than controls. However, when women who underwent abdominal delivery for previous myomectomy (n = 5) were excluded from analysis, there was no significant difference in the incidence of Caesarean delivery. Overall, there was no difference in the incidence of obstetric complications between groups even when the data was stratified for large and/or multiple leiomyomas. The discovery of uterine leiomyomas by gestational ultrasound does not appear to place the patient at increased risk for preterm labour, early delivery, or other untoward pregnancy outcomes.