Portomesenteric vein thrombosis (PMVT) is a rare post-operative complication of bariatric procedures, occurring in between 0.3% and 1% of cases. A structured questionnaire consisting of 27 items was available online to members of the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) to investigate the occurrence of PMVT. A total of 89 bariatric surgeons from 61 countries participated. Twenty-six (29.21%) reported at least one case of PMVT (46.15% males; 53.84% females). The surgery most associated with PMVT occurrence was sleeve gastrectomy (84.6%), followed by Roux-en-Y gastric bypass (RYGB) (7.69%), and laparoscopic adjustable gastric banding (LAGB) (7.69%). The time gap between surgery and PMVT was 19.28 ± 8.72 days. The predominant symptom was abdominal pain in 96.15% of patients, followed by fever in 26.9%. Complete occlusion of the portal vein was reported in 34.6% of cases, with involvement of the portal system in 69%, extension to the superior mesenteric district in 23%, and extension to the splenic vein in two patients (7.7%). Our survey, which is the largest regarding PMVT to date, revealed a diffuse lack of standardization in the choice, duration, and dosing of prophylaxis regimens as well as treatment modalities, reflecting the literature gap on the topic.