The Utah PLT and the corresponding Utah Numerical Scoring System resulted from over 30 years of scientific research and scientific peer review. This technique provides some of the highest rates of accuracy and repeatability of any polygraph examination protocol. The Utah PLT was created by psychologists based upon known and proven principles of psychology and psychophysiology (Raskin and Honts, 2002). The Utah Scoring System uses a conservative approach in assigning values. This ensures that scores are assigned to reactions that are clearly different from other reactions. Although this conservative approach may result in an inconclusive finding after three testing charts, requiring two additional charts, the additional charts should increase confidence in the results. This paper describes the test structure and administration, the three-question format, the four-question format, the testing procedure, test data analysis, and decision criteria. 12 figures and 13 references