We used an investigational technique for the biopsy of intraocular tumors to aid in the diagnosis of three choroidal tumors. A three-port trans-pars plana vitrectomy was performed in conjunction with retinotomy, tumor biopsy, endophotocoagulation, and air-fluid exchange. Vitrectomy was used to decrease the amount of traction secondary to retained vitreous after intraocular surgery. Retinotomy sites were chosen under microscopic control to avoid large caliber retinal vessels. Then a modified tumor-aspiration technique, together with endophotocoagulation and aspiration of intraoperative vitreous hemorrhages, provided an opportunity to sample tumor tissue continually at varied depths. We have added standard vitreous surgery concepts, techniques, and instrumentation to produce vitrectomy retinotomy aspiration biopsy of choroidal tumors.