This research focuses on the development and empirical validation of a model of software piracy behavior in Vietnam on the basis of institution isomorphism theory, deterrence theory, and expected utility theory. A survey of 145 respondents and PLS (Partial Least Square) were utilized for analysis. The test of this study reveals that mimetic pressure is the greatest significant factor to influence software piracy intention. Coercive pressure, normative pressure, punishment severity, and software cost are also significantly related to the intention. However, punishment certainty does not have a significant influence on software piracy.