Patients with inflammatory bowel disease (IBD) have a 1.5-3.5-fold higher risk of thromboembolism when compared to the non-IBD population and the risk is much more prominent at the time of a flare. Arterial thromboembolism (ischemic stroke, focal white matter ischemia, cardiac ischemia, peripheral vascular disease and mesenteric ischemia) and venous thromboembolism (deep vein thrombosis and pulmonary embolism, cerebral venous sinus thrombosis, retinal, hepatic, portal and mesenteric vein thromboses) belong to the group of underestimated extraintestinal complications in IBD patients, which are associated with a high morbidity and mortality rate (the overall mortality is as high as 25 % per episode). Thromboembolism occurs in younger patients compared to the non-IBD population and has a high recurrence rate. Multiple risk factors are involved in the etiopathogenesis, but the acquired ones play the key role. Congenital alterations do not occur more frequently in IBD patients when compared to the non-IBD population. Standardized guidelines for the prophylaxis of thromboembolism in IBD patients are urgently needed and these should be respected in clinical practice to avoid preventable morbidity and mortality.