Multiple myeloma, Waldenström's macroglobulinemia and benign monoclonal gammopathy are examples of diseases in which there is an uncontrolled proliferation of cells involved in antibody synthesis. Myeloma and macroglobulinemia are considered malignant diseases, whereas monoclonal gammopathy is benign or possibly a pre-myelomatous condition. Following a brief review of the immunoglobulins the various clinical manifestations of these disorders are described. The ophthalmic signs of these disorders can be seen in every ocular structure.