Founded in 1881, the Vereniging tegen de Kwakzalverij (VtdK) is one of, if not the oldest skeptical organisation in the world. It focuses on good practice in medicine, and seeks to protect patients against potentially harmful or useless alternative therapies. Its main activities include the publication of its quarterly magazine Nederlands Tijdschrift tegen de Kwakzalverij (‘Dutch Magazine Against Quackery’) in print and online, and hosting an annual symposium, during which the mock Meester Kackadoris Prize is awarded to the person or organisation that is deemed to have promoted quackery the most that year. It also maintains a quackery encyclopaedia.
In 2011, the society had more than 2000 members. Its spokespeople regulary feature in the media to warn against the latest health fad or unproven exotic treatments.