The need for empirical, objective, clear, and practical outcome measures for therapy has long been recognized by clinicians and researchers. Pragmatic tools for objective determination of the efficacy of therapy have been scarce in clinical practice settings. Heart rate variability (HRV) is increasing in popularity for use in clinical settings as a measure of treatment success. Since HRV is stable and placebo-free, it has the potential to meet this need. Thirty-nine cases are presented from the clinical practices of the authors and three other clinicians where HRV was used as an outcome measure for Thought Field Therapy (TFT). The cases included TFT treatments which addressed a wide variety of problems including phobias, anxiety, trauma, depression, fatigue, attention deficit hyperactivity disorder, learning difficulties, compulsions, obsessions, eating disorders, anger, and physical pain. A lowering of subjective units of distress was in most cases related to an improvement in HRV. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1193–1206, 2001.