The Social Vulnerability Scale (SVS), a 22-item informant report of vulnerability to exploitation and, in particular, financial exploitation of older adults, was administered to 266 respondents who assessed the social vulnerability of a significant other aged 50 years or over, either a person with dementia or other neurological condition (n=116), or a healthy adult (n=150). Exploratory factor analysis in the combined sample revealed a 15-item 2-factor solution labeled gullibility and credulity. Stability in factor structure was established in an independent sample (n=123) using confirmatory factor analysis, and sound reliability (internal consistency) and validity (known-groups) were demonstrated. The SVS15 is a potentially useful instrument for assessing older adults' vulnerability to exploitation. (Published Abstract)