Patients 21 years of age and older with one to three metastatic brain tumors may be eligible for this study. Participants will have a medical history and physical examination, blood and urine tests, an electrocardiogram, and chest x-ray. They will then be randomly assigned to undergo either surgery or SRS. Before either procedure, patients will have a magnetic resonance imaging (MRI) scan. MRI uses a strong magnetic field and radio waves to obtain images of the brain. Patients scheduled for SRS will have a computed tomography (CT) scan in addition to the MRI. CT uses X-rays to obtain images of the brain. During the CT, a contrast agent is injected through an IV tube placed in a vein to enhance the CT images. For both the MRI and CT tests, the patient lies on a table that slides into a cylindrical scanner. The MRI usually lasts between 45 and 90 minutes, while the CT scan lasts for about 30 to 60 minutes.