Aim: The authors aimed to study larger intramural leiomyoma with a size of ≥ three cm on pregnancy outcome of singleton pregnancies compared with control group. Materials and Methods: The hospital records of all pregnancies followed between years of 2009 and 2013 were searched for the diagnosis of intramural leiomyoma in the second trimester ultrasonographic screening, past medical history, demographics, pregnancy follow up, and pregnancy outcomes of pregnant women. In the data analyses, 112 singleton pregnant women with intramural leiomyoma were included in the study group and 168 singleton pregnant women without leiomyoma were included in the control group. Results: The presence of pregnancy associated leiomyoma was found to be a risk factor for abortion (odds ratio (OR):12.6, 95% confidence interval (CI) 2.5?63.6) hospitalization for pain (OR: 19.6, 95% CI 5.8?66.5), premature rupture of membranes (OR: 6.7, 95% CI 1.4-32.4), oligohydramniosis (OR: 5.3, 95% CI 1.4?20.0), preterm birth (OR: 4.7, 95% CI 1.9?11.6), and breech presentation and other abnormal presentations (OR: 9.7, 95% CI 2.8?34.2) and neonatal intensive care need (OR: 3.0, 95% CI 1.2-7.5). No correlation with the rate of intrauterine growth restriction, intrauterine fetal death, placenta previa, abruption of placenta, and cesarean section was found. Conclusions: Pregnancy associated intramural leiomyoma is a risk factor for some perinatal complications and these results may be useful for prenatal counseling.