The definition of intellectual disability, according to the American Association on Intellectual and Developmental Disabilities, includes the assumption that adequate supports should improve a person’s functioning. Consequently, support needs have to be assessed to plan services for persons with intellectual disability. The Supports Intensity Scale (SIS; J. R. Thompson et al., 2004) is a standardized instrument for assessing support needs and their intensity. This study was designed to estimate the interrespondent, interinterviewer coefficients of the French version of the SIS. Approximately 40 persons with intellectual disabilities from Quebec, a Canadian province, participated in this study. For each participant, 2 respondents and 2 interviewers were identified and 3 French SIS questionnaires were filled out. Results are presented and discussed compared with those obtained with the original, English-based SIS.