Entrepreneurs operate in uncertain environments in which there are many demands on their time and attention. Furthermore, they must be able to effectively pursue long-term goals in order to be successful in their entrepreneurial endeavors. This study investigates the self-regulatory factor known as grit – perseverance and passion for long-term goals, and a construct from the field of family systems known as differentiation of self. Structural equation modeling is used to examine the extent to which these constructs, along with subjective well-being, are positively associated with entrepreneurial performance and success. Results indicate that differentiation of self and subjective well-being are positively related to grit, and grit and subjective well-being are positively associated with both career success and firm performance.