Abstract: The invention provides human monoclonal antibodies, scFv antibodies, scFv-Fc fusions, a dAb (domain antibodies), Fab, Fab? and F(ab)?2 fragments, single chain antibodies and/or minibodies that specifically bind to CXCR4. Also provided are methods of treating and/or preventing a CXCR4 disease or disorder such as cancer and X4-tropic HIV-I infection as well as uses of such antibodies and antibody fragments in the manufacture of a medicament for the treatment or prevention of a CXCR4 disorder. The invention also provides methods of preventing diseases or disorders associated with CXCR4 function or expression. The invention further provides for the use of the antibodies (or fragments thereof) of the invention in the manufacture of a medicament for the prevention of diseases or disorders associated with CXCR4 expression. Also provided are methods of treating or preventing cancer metastasis in a patient suffering from a cancer involving tumor cells that express CXCR4.