The present review by the IBD-Dach group provides a comprehensive summary of the mode of action, clinical development, approval, efficacy and safety aspects of the novel anti-p40 antibody Ustekinumab. The review provides current data, including the large clinical trials as well as smaller case series and work outside the field of inflammatory bowel diseases for shedding more light into special situations. Together, the data indicate that Ustekinumab shows clinical efficacy as well as a good safety profile for the treatment of Crohn's disease.