The Willem C. Vis Moot Court (often simply called "Vis Moot") is the world's largest moot court competition and unites around 4.000 students and practitioners each year in Vienna.

The Vis Moot Court was founded in 1993 to promote the use of the CISG through means of international commercial arbitration. Thus, each year the participating students debate current questions of international arbitral procedure and commercial law. In the past years the "Vis Moot Problem" has covered trending topics ranging from legal questions related to import tariffs to the production of renewable energy.

The number of participating teams rises constantly each year. In the last years as many as 380 universities from more than 80 countries have enabled their students to participate in the Vis Moot Court. The participating students come from all parts of the world - may it be Cambridge, Johannesburg, New York, Rio de Janeiro or Singapore.

In order for the participating students to meet one another and to practice their debating skills as much as possible, many pre-moot courts are organised each year. In the past, the team of WU Vienna participated amongst others in pre-moot rounds in Lisbon, Dubai, Helsinki, Prague, Belgrade, St. Petersburg, Riga and Zurich.

While the locations of the pre-moots may vary every year, the finale is always held in Vienna in the week before Easter. Thus, each Vis Moot season spans from October until April. The first months of each season always enable the students to write two legal memoranda, which subsequently may serve as basis for a Master thesis. After the written exchange of arguments, the oral debating begins each year late in January and enables the teams to travel around the world to meet another and to practise their debating skills.