Traditional corticosteroids represent a well-established and effective treatment for active ulcerative colitis (UC). However, the severity of their systemic side effects, led in recent years to look for new steroid molecules that could reduce them, maximizing the anti-inflammatory activity. Budesonide has been one of the most studied steroid compounds and it has been approved for the treatment of mild to moderate active Crohn's disease (CD). In order to extend the release until the distally located inflammation, budesonide has been coupled with a controlled delivery system, called Multi-Matrix system (MMX), already successfully tested with oral mesalazine for the treatment of distal UC. After in vitro and in vivo models, the efficacy of Budesonide-MMX has been investigated in active UC with a first small phase II study, and partially encouraging results. This article will review the evidences on the use of budesonide in inflammatory bowel diseases and will discuss the role of Budesonide-MMX in active UC nowadays.