Eugen Bircher was a strong advocate of diagnostic arthroscopy as shown in several papers on the topic of internal derangements of the knee published between 1921 and 1926. During that time, he performed about 60 endoscopic procedures, which usually preceded a meniscectomy. We believe that this was the first time arthroscopy was used in a large scale for clinical purposes. Bircher was the head surgeon of the busy provincial Aarau General Hospital, a right-wing politician, and a highly ranked army officer. His interest in knee surgery was supported by his friend Fritz Steinmann, who was the "man of the pin" and an early promoter of skeletal traction for fracture treatment. Bircher believed in the early surgical treatment of meniscal lesions and, later, in the reconstruction of cruciate ligament lesions. He used the Jacobaeus thoracolaparoscope for arthroscopy, but it had poor endoscopic qualities. The electric lamp at the tip of the optical device was not mechanically protected and was therefore endangered by every manipulation within the joint space. Also, the 90 degrees optical system delivered a dark image. By the late 1920s, Bircher had developed the technique of double-contrast arthrography, and he gave up endoscopy by 1930. In 1935, he left surgery and took a military command in the Swiss army; later he was a representative of the Farmers Party in the National Parliament until his death.