We described the development and psychometric properties of the Community Living Attitudes Scale, Mental Retardation Form (CLAS-MR), a 40-item measure based on the input of self-advocates and focused on contemporary community living philosophies. The CLAS-MR, which consists of four subscales that tap attitudes about people with mental retardation, demonstrated acceptable internal consistency, retest reliability, and construct validity with samples of 104 college students and 283 community members. Using data from a sample of 355 staff members from community agencies, we confirmed the factor structure of the measure. Given the importance of attitudes toward persons with mental retardation in policy making and community inclusion, the CLAS-MR can help chronicle the diffusion of the new paradigm of empowered community living for persons with mental retardation.