This 2-part study described the development and preliminary validation of the State Mental Contamination Scale (SMCS), a multi-item self-report measure of state mental contamination. In Study 1, community adults (N = 211) in the United States were randomly assigned to a pathogen disgust, moral disgust, or neutral condition and then completed the SMCS. Study 1 results supported a 1-factor structure of the SMCS items. Scores on the SMCS items evidenced good internal consistency and strong interitem correlations. SMCS scores were significantly greater following the 2 disgust conditions relative to the neutral condition and a full range of SMCS scores were found in the disgust conditions. An independent sample of community adults (N = 121) from the United States participated in Study 2 to extend Study 1 results. Study 2 results indicated that SMCS scores were manipulated independently of trait mental contamination, more strongly related to convergent than a discriminant measure, and shared unique variance with a criterion measure after controlling for convergent measures. The future use of the SMCS is discussed.