Objective Iliac vein stenting is increasingly being explored for the treatment of chronic venous insufficiency. While venography is considered the gold standard for assessing iliac veins, some have proposed that intravascular ultrasound should be utilized instead due to its greater sensitivity at detecting stenotic lesions. Routinely, our service uses both intravascular ultrasound and venography, but we have noted that some patients cannot tolerate dye due to allergy, renal insufficiency, or deemed high-risk by the interventionalist due to uncontrolled medical co-morbidities. This study aimed to investigate whether forgoing dye had an impact on iliac vein stent thrombosis. Methods From 2012 to 2016, 1482 iliac vein procedures (91 intravascular ultrasound-only and 1391 intravascular ultrasound plus venography) were performed on 992 patients who failed conservative treatment for chronic venous insufficiency. Our mean patient age was 65.8 years (range 21–99; SD ± 14.3) with 347 male and 645 female patients. The clinical presenting symptoms per clinical–etiology–anatomy–pathophysiology classification for the intravascular ultrasound-only cohort were C1:0, C2:3, C3:31, C433, C5:5, C6:20 and for the intravascular ultrasound plus venography cohort were C1:0, C2:24, C3:566, C4:583, C5:30, C6:188. Stent thrombi that developed within or at 30 days of stenting were categorized as early and greater than 30 days as late. Transcutaneous duplex ultrasound classified stent thrombi as either partial or occlusive. Our average follow-up time was 19.4 months (0–42, SD ± 12.5). Results A total of 2.2% intravascular ultrasound-only patients versus 2.75% intravascular ultrasound plus venogram patients developed early stent thrombosis, p = 0.35. Early partial stent thrombosis occurred in 1.1% of the intravascular ultrasound-only group versus 2.6% of the intravascular ultrasound plus venogram group, p = 0.38. Early occlusive stent thromboses occurred in 1.1% of intravascular ultrasound-only patients and 0.15% of intravascular ultrasound plus venogram patients, p = 0.06. Late stent thromboses developed in 4% of patients in the intravascular ultrasound-only cohort and 4% in the intravascular ultrasound plus venogram cohort, p = 0.97. Late partial stent thromboses occurred in 2.7% of intravascular ultrasound-only patients versus 2.6% in intravascular ultrasound plus venogram patients, p = 0.99. Late occlusive stent thromboses occurred in 1.3% of intravascular ultrasound-only patients versus 1.4% of intravascular ultrasound plus venogram patients, p = 0.95. Moreover, the formation of any stent was 6.2% in the intravascular ultrasound-only versus 6.75% in the intravascular ultrasound plus venogram group, p = 0.55. Conclusion Results of our study show no significant difference in stent thrombosis between the intravascular ultrasound-only and intravascular ultrasound plus venogram cohorts. This concludes that using intravascular ultrasound alone is safe for iliac vein stenting.