Abstract: A swivel arm assembly for connecting a surgical microscope to a stand comprises a microscope interface connected to a suspension device by a swivel arm. The swivel arm includes an approximately isosceles two-armed support lever and an approximately isosceles two-armed operating lever pivotal relative to the support lever about an axle connecting the vertices of each lever. An upper shaft at an upper end of the support lever and a lower shaft at a lower end of the support lever are coupled connected to respective upper and lower operating ends of the operating lever by toggle joints, whereby moments arising at one shaft are transmitted to the other shaft at a 1:1 ratio. The swivel arm is guided for motion in a vertical plane by a parallel carriage guide having a first and second orthogonal carriage guides, and an adjustable carriage guide connects the upper shaft to the suspension device to permit the center of gravity of loading to be moved.