Attending college is a common experience in the United States, with about 7.1 million students projected to enroll in public 4-year colleges and universities in Fall 2018, and institutions expecting to award 1.9 million bachelor's degrees for the 2018-2019 academic year. Because college represents a significant investment of money and time and students expect positive outcomes, such as employment and increased earning potential, it is important to consider the factors that help students to achieve success during and after their college education. One characteristic of a college student's experience that is correlated with positive outcomes is the presence of a mentor--often a professor, advisor, coach, or even older peer--who provides a helpful, supportive, and personal relationship with a student, and often serves as a role model. These mentoring relationships are associated with increased academic achievement and college adjustment, particularly for minority, first-generation, and at-risk students. Given the value of a mentoring relationship for college student success, it is important to establish a theory-driven quantitative measure of the mentoring relationship for empirical purposes. A quantitative measure of mentorship allows for wide-scale assessment of the characteristics of mentoring relationships and provides a means to assess student outcomes associated with mentorship experiences. Despite the need for such a measure, no widely established assessment exists. The College Student Mentoring Scale (Crisp, 2009) has been used in community college samples, but its factor structure was not as robust among students at a doctoral-granting institution (Crisp & Cruz, 2009). In a previous study, the authors used developmental theory (see Baxter Magolda, 2009; Kegan, 1994) to develop a number of items that assess college students' experience being mentored, and the authors empirically derived the Mentor Relationship Assessment (MRA), an internally reliable 24-item measure through exploratory factor analysis on data from 321 students. In this study, the authors aimed to confirm the factor structure and internal reliability of this measure in a new sample of students from a different university. Findings confirm that the MRA has a 4-factor structure that has been replicated in a separate sample.