To the Editor.— False positive results in serological tests for syphilis occur in numerous pathological states, which include rheumatoid arthritis, lupus erythematosus, and many others. Thyroid diseases such as hyperthyroidism, hypothyroidism, diffuse nontoxic goiter, acute subacute thyroiditis, and chronic thyroiditis have not been studied thoroughly for the incidence of false reactive syphilis serological tests. Although numerous workers have suggested that various thyroid disorders could be based on an autoimmune reaction, the only thyroid disease that has been reported to give a false reactive test is Hashimoto's disease, described by Selenkow et al in 1961. 1 A total of 1,102 cases of various thyroid diseases which include hyperthyroidism, hypothyroidism, diffuse nontoxic goiter, and thyroiditis were reviewed between 1961 and 1969 at Jackson Memorial Hospital. The incidence of reactive VeneralDisease Research Laboratory tests (VDRL) was recorded; out of the total 1,102 patients, only 7 patients were shown to have reactive VDRL