We designed a suction attachment for the radiosurgical treatment of intraocular malignancies with the Leksell gamma unit (Gamma Knife). Our device consists of a circular suction chamber and an adjustable unit to be fixed to the Leksell stereotactic head frame. All components are made of plastic materials in order to avoid artifacts in CT or MRT imaging. A permanent suction of 600-800 mbar is provided by a standard vacuum pump, powered by a portable battery. Suction times up to 40 min were well tolerated in all cases. We successfully used this device, performing 17 radiosurgical treatments in 8 patients with large or extra-large uveal melanomas and one patient suffering from a choroidal metastasis.