The American Medical Association (AMA) Council on Scientific Affairs has reviewed the data on the validity and accuracy of polygraph testing as it is applied today. The use of the control question technique in criminal cases is time honored and has seen much scientific study. It is established that classification of guilty can be made with 75% to 97% accuracy, but the rate of false-positives is often sufficiently high to preclude use of this test as the sole arbiter of guilt or innocence. This does not preclude using the polygraph test in criminal investigations as evidence or as another source of information to guide the investigation with full appreciation of the limitations in its use. Application of the polygraph in personnel screening, although gaining in popularity, has not been adequately validated. The few limited studies that have been performed suggest no greater accuracy for the types of testing done for this purpose than for the control question polygraph testing used in criminal cases. The effect of polygraph testing to deter theft and fraud associated with employment has never been measured, nor has its impact on employee morale and productivity been determined. Much more serious research needs to be done before the polygraph should be generally accepted for this purpose.