At the Queens General Hospital the Kline precipitation test by both diagnostic and exclusion procedures is done routinely. If both procedures give a completely negative result, no other serologic test is considered necessary. Whenever the Kline test shows any degree of positiveness, a Wasserman test is performed. The results of the precipitation and of the complement fixation test do not always agree exactly. This has caused some confusion in the minds of the clinicians. In an attempt to clear up this doubt, a study was conducted to interpret the significance of the serologic tests in terms of clinical syphilis. As Moore1 recently pointed out, each laboratory must determine the reliability of its own reports if they are to have any value. That serologic tests are of prime importance in the diagnosis of syphilis must be accepted when it is considered how few patients give a history or clinical evidence