The construction industry is experiencing more serious ethical problems than ever before. The objectives of this study are to (1) identify the inducers of individuals’ unethical behavior in contractors’ organizations in the Chinese construction industry; and (2) investigate the interrelationships among these inducers. Based on a literature review and interviews, 18 factors inducing unethical behavior were identified, and a questionnaire survey was performed, which garnered 129 responses. The results showed that 13 inducers were significantly important, and that “cost pressures,” “inadequate sanctions,” and “absence of ethics systems” were the top three inducers of unethical behavior. Additionally, the 18 inducers were categorized into 5 underlying groupings: culture-related inducers; policy environment; project pressures; individual traits; and organizational climate. Further analysis results indicated that culture-related inducers indirectly influence organizational climate through their direct impact on policy environment, project pressures, and individual traits. The proposed framework describing the inducers and the intergrouping relationships provides an understanding of the formation mechanism of contractors’ unethical behavior