OBJECTIVES: This study was conducted to compare a self-administered hand symptom diagram with other diagnostic tests and to assess its value in the diagnosis of carpal tunnel syndrome. METHODS: A self-administered hand symptom diagram has been developed for the evaluation of upper extremity paresthesias. A rating system was devised to classify the diagrams into four categories: classic, probable, possible, or unlikely carpal tunnel syndrome. Before nerve conduction testing, a medical history and demographic data were collected, a physical examination was conducted, and a hand symptom diagram was obtained from each patient. The diagram ratings of 85 patients(130 hands) were evaluated by an occupational and environmental medicine physician and a nerve conduction study was administered and interpreted by a rehabilitation medicine physician. RESULTS: Of 85 patients, 48(56.5 %) had carpal tunnel syndrome confirmed by nerve conduction study. A hand symptom diagram rating of classic or probable CTS had a sensitivity of 75.6 %, a specificity of 59.6 %, a positive predictive value of 73.8 % and a negative predictive value of 62.0 %. Of the combinations of clinical findings in carpal tunnel syndrome, a classic or probable hand symptom diagram or a positive Tinel's sign showed the highest sensitivity. CONCLUSIONS: A self-administered hand symptom diagram is valuable in the diagnosis of carpal tunnel syndrome among patients with upper extremity paresthesias. It is a useful diagnostic tool and may be valuable for occupational or population screening.