There is great interest in, but few instruments to assess, multiple levels of support and community resources from a social-ecological perspective. This study evaluated the psychometric characteristics of the Chronic Illness Resources Survey (CIRS) and its sensitivity to a multifaceted social-ecological intervention to enhance personally relevant community resources supportive of healthful lifestyles. Participants were 293 post-menopausal women having type 2 diabetes who were part of a multiple-behavior lifestyle change program. Key measures included the CIRS, a validated Food Frequency Questionnaire, the Kristal Fat and Fiber Behavior Questionnaire, the CHAMPS Activities Questionnaire for Older Adults, and other measures of social support. Results revealed that the CIRS displayed good psychometric characteristics in this new sample, was significantly correlated as predicted with established measures of social support, was sensitive to intervention, and partially mediated the effects of intervention on both dietary and physical activity outcomes. The 22-item CIRS scale appears useful for assessing multilevel support resources, predicting successful behavior change and detecting social-ecological intervention effects.