Thirty-nine patients with polymorphous light eruptions (PMLE) were studied for the presence of circulating antinuclear antibodies and the deposition of immunoglobulin in the dermal-epidermal zone. The diagnosis of PMLE was determined clinically and confirmed by phototesting procedures. The serum antinuclear antibody test was questionably positive (±) in one of 35 patients so tested with human leukocyte or rat liver nuclei. Dermal-epidermal zone immunofluorescence was negative in each of 25 patients. These findings indicate that PMLE is not part of the lupus erythematosus (LE) spectrum of disease. Further, we feel that these testing procedures are of value for differentiating these two diseases.