Purpose Completely occlusive acute–subacute portal and mesenteric vein thrombosis (PVMVT) with severe complications is fatal. Endovascular treatments (EVTs) of acute–subacute PVMVT are not standardized. Thrombectomy combined with continuous catheter-directed thrombolysis is considered an effective treatment. Here, we aimed to evaluate the outcome of EVTs of completely occlusive acute–subacute PVMVT with severe complications in patients without cirrhosis. Materials and methods Nineteen patients (nine men and 10 women; age, 60.1 ± 16.8 years) with completely occlusive acute–subacute PVMVT were retrospectively assessed. Acute–subacute PVMVT was defined as symptom onset within 40 days, with no cavernous transformation observed on contrast-enhanced computed tomography. The patients were treated with EVTs, a combination of thrombectomy (including aspiration thrombectomy, plain old balloon angioplasty, single injection of thrombolytic agents, and stent placement) and continuous catheter-directed thrombolysis. Kaplan–Meier analyses were performed to assess all-cause mortality, acute–subacute PVMVT-related mortality, and portal vein (PV) patency. The degree of recanalization and patency of PV, complications, factors related to acute–subacute PVMVT-related mortality, and factors related to patency of PV were also evaluated. Results The all-cause and acute–subacute PVMVT-related mortality rates were 36.8% (7/19) and 31.6% (6/19), respectively. Seven (36.8%) and 11 (57.9%) patients achieved complete and partial recanalization, respectively. Among the 18 patients who achieved recanalization, follow-up images after 608.7 ± 889.5 days confirmed recanalization in 83.3% (15/18) patients, and 53.3% (8/15) of these patients achieved patency of PV. Seven patients (36.8%) developed complications, and two (10.5%) required interventional treatment for complications. Deterioration of liver function significantly worsened the prognosis ( P = 0.046), while anticoagulation therapy significantly maintained portal patency ( P = 0.03). Conclusion This endovascular method for acute–subacute PVMVT, which combines thrombectomy and continuous catheter-directed thrombolysis EVT approach was effective for thrombus resolution. However, further studies must define conditions that improve patient prognosis.