In the past few years there has been a renewal of interest in false positive serologic reactions. Partly because of the increased number of tests performed as a routine on apparently nonsyphilitic persons, there is a better realization of the number of causes of false positive reactions. There are three main groups of such reactions: (1) those due to technical error, a relatively infrequent occurrence; (2) those reactions encountered in persistently false positive human serums resulting from the presence of a reagin-like component which has been demonstrated in various animal serums;1(3) those positive serologic reactions which are found in patients with organic disease other than syphilis; they occur regularly in yaws, fairly constantly in leprosy and malaria and less frequently in many other diseases.2Further information and conclusive identification of those diseases causing positive reactions are particularly of clinical interest when the reactions are strongly positive and