This study draws upon the theory of planned behavior to empirically test a model which clarifies the relationships between attitude toward behavior, subjective norm, and perceived behavioral control and university students' social entrepreneurial intentions as well as revealing the moderating role of entrepreneurship education and academic major. Through multiple linear regression analysis, we tested our hypotheses on a sample of 832 college students (342 from three universities in Taiwan and 490 from four universities in Thailand). Results indicate that all aspects of the theory of planned behavior have a positive and significant impact on social entrepreneurial intentions. More interestingly, the positive effects of attitude toward behavior and perceived behavioral control on social entrepreneurship intention are strengthened when students attend entrepreneurship program at university and have a non-business major. On the basis of three-way interaction analysis, our findings suggest that college students' social entrepreneurship intention is at the highest level when non-business major students have favorable attitude towards behavior, perceive a strong behavioral control, and receive entrepreneurial education. This paper sheds new lights on the behavioral mechanisms that determine students' intention to engage in social enterprises. The theoretical contributions and practical implications for educational policy are discussed.