An attempt was made to classify 100 patients who complained of deep, poorly localized, and vaguely described facial pain but whose symptoms could not be ascribed to trigeminal neuralgia, glossopharyngeal neuralgia, postherpetic neuralgia, or obvious disease of the teeth, throat, nose, sinuses, eyes, or ears. In 53 cases the trouble was finally ascribed to psychiatric illness such as depression, hysteria, or schizophrenia. In 33 cases it was possible to identify either organic causes such as tumors or physiological disturbances such as abnormal vasodilator activity. In 14 patients neither psychiatric nor physical causes were identified and the etiology remained undetermined. Such patients should be treated conservatively, since ill-advised operations can result in grief for both patient and surgeon.