Previous studies associated disgust proneness and thought-action fusion with mental contamination. The present study aims to investigate the associations among disgust propensity, disgust sensitivity, contamination-related thought-action fusion, mental contamination, and related factors, including internal/external negative emotions and washing urges. One hundred eighty female participants filled out the questionnaires assessing disgust proneness and contamination-related thought-action fusion and rated their baseline feeling of dirtiness and negative emotions. They listened to an audiotape instructing them to conceive themselves being subject to a nonconsensual kiss attempt by a male and rated their mental contamination, negative emotions, and the urge to wash levels. The path analysis indicated that disgust propensity and contamination-related thought-action fusion were significantly associated with disgust sensitivity. Their association with the urge to wash was positively mediated by mental contamination and negative emotions. This is the first study examining the above-mentioned cognitive and affective factors in a mediation model using a non-Western population. Our findings are crucial for understanding mental contamination and washing behavior.