Objective The purpose of this study was to assess the clinical features of phlegmasia cerulea dolens and present the treatment outcomes with rheolytic thrombectomy device. Methods From January 2014 and March 2019, 329 patients were diagnosed and hospitalized for acute iliofemoral deep vein thrombosis, and among those patients, seven patients diagnosed with lower extremity phlegmasia cerulea dolens were consecutively enrolled. Diagnosis of phlegmasia cerulea dolens was initially made on clinical findings followed by imaging with Doppler ultrasound. The rheolytic thrombectomy device was used in all patients with a combination of catheter-directed thrombolysis as an adjunctive therapy to facilitate more rapid thrombus clearance except for one patient who had a contraindication to the use of tissue plasminogen activator. Results Seven patients (four men, three women; median age, 63 years, range 52–68 years) were included. One patient had a relative contradiction to thrombolysis due to history of coronary artery bypass graft surgery; all other patients underwent pharmaco-mechanical thrombectomy with power pulse mode. The upper limit of 480 s was completed in all patients, and this time was not exceeded to prevent hemolysis-related complications. Six Fr catheters were used in four (57.1%) patients, and 8 Fr catheters were used in three patients (42.9%). Mean thrombolytic infusion duration was 28 ± 6.2 h for patients who received tissue plasminogen activator. After catheter-directed thrombolysis, total radiological success was achieved in two patients, and partial radiologic success was achieved in five patients; however, in all seven patients, clinical success was achieved. The mean duration for complete regression of cyanosis was 18.9 ± 8.1 h. Although no patients required blood replacement, mean decreases in hemoglobin and hematocrit were 2.7 ± 1.37 g/dl and 6.42 ± 4.47%, respectively. Acute kidney injury developed in three patients (42.9%). One patient required continuous renal replacement therapy. No cardiac complication was observed. One (14.3%) patient died of ventilator-related pneumonia on postprocedural day 10. The median duration of intensive care unit stay and hospital stay were 72 h (min–max: 24–264 h) and six days (min–max: 5–33 days), respectively. Conclusion Rheolytic thrombectomy was less invasive and effective strategy for early stage phlegmasia cerulea dolens at creating rapid thrombus clearance to establish clinical success and facilitate more conservative management with catheter-directed thrombolysis.