Otto Lanz (1865-1935) was a Swiss surgeon trained by Theodore Kocher in Berne. In 1902, he was invited to become professor of surgery at the Binnengasthuis hospital in Amsterdam. He was an outstanding surgeon who was well known for his surgery of the thyroid gland and the appendix. He introduced the eponymous Lanz's point in acute appendicitis and also the girdle incision for appendectomy. He was a strong proponent of 'early' appendectomy, as opposed to the conservative approach, at that time the treatment of choice. He was a great connoisseur and passionate collector of Italian Renaissance art. His Italian works of art have been exhibited in a special 'Lanz Hall' at the Rijksmuseum in Amsterdam. During World War II, his collection was acquired for Hitler's proposed Führermuseum but was returned to Amsterdam after the war. A portrait by Jan Toorop and Lanz's former villa on the Museum Square in Amsterdam remind us of this colourful surgeon.