Peripheral blood polymorphonuclear leucocytes (PMN) and cryoglobulins were isolated from patients with systemic lupus erythematosus (SLE). Fluorescent inclusions were found in PMN. Normal donor PMN were incubated with the sera and cryoglobulins from SLE patients. In most cases inclusions were observed after incubation. The high incidence of anti-IgG activity in phagocytosed cryoglobulins confirms the importance of the rheumatoid factor in phagocytosis of immune complexes. It is concluded that phagocytosis of cryoglobulins supports the suggestion that cryoglobulins are a subpopulation of immune complexes.