To investigate the various clinical courses of patients with amyotrophic lateral sclerosis (ALS), we developed a telephone survey system for determining the activities of daily living (ADL) status of patients with ALS. In this system, every 3 months, clinical research coordinators (CRCs) conducted a telephone survey using the flow charts of the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R; Japanese version). To confirm the reliability of the results of the telephone survey, we compared the scores of 37 ALS patients obtained in the telephone surveys (telephone scores) to the scores obtained during clinical examinations by neurologists (neurologists' scores). The mean (SD) age of the included patients was 62.6 (11.8) years. Eighteen patients answered the surveys themselves, whereas the primary caregivers of 19 patients answered the surveys for the patients. Before the study, we informed the CRCs of the study plan, general knowledge of ALS, procedures of the telephone survey, ethical issues relevant to the study, and requisite considerations for ALS patients and caregivers. The intraclass correlation coefficient (ICC) between the telephone scores and the neurologists' scores in the 37 ALS patients was 0.97 (95% confidence interval [CI], 0.94-0.98). The kappa statistics of 12 questions of the ALSFRS-R between the telephone scores and the neurologists' scores ranged from 0.58 to 0.85. The ICC of the scores of the 18 cases in which the patients answered the telephone questions themselves was 0.96 (95% CI, 0.89-0.98). The ICC of the scores of the 19 cases in which the caregivers answered the telephone questions was 0.97 (95% CI, 0.92-0.99). These results showed a good reliability of the telephone survey, regardless of whether the patients themselves or the caregivers answered telephone questions. In 2006, a longitudinal multicenter study of Japanese ALS patients was initiated called the Japanese Consortium for Amyotrophic Lateral Sclerosis research (JaCALS). In the JaCALS, prospective clinical information was obtained using this telephone survey system. Of the 284 ALS patients who were registered at JaCALS over a year ago, 93% were followed up and provided ALSFRS-R scores and information relevant to prognosis. We have established an efficient and reliable telephone survey system for studying the longitudinal clinical courses of patients with ALS.