This study investigated effects of Ratemyprofessors.com and university student evaluations of teaching on students' course decision-making and self-efficacy in an ethnically diverse undergraduate sample. It also investigated if these effects were impacted by evaluation positivity. Additionally, the study explored if attitudes toward Ratemyprofessors.com were related to student gender, college class, and age. Participants were 73 undergraduates who were exposed to positive and negative evaluations about fictitious professors; participants were informed that the evaluations originated from Ratemyprofessors.com or university student evaluations of teaching. Evaluation positivity but not type influenced students' intention to enroll in the professor's course, but not how seriously they would consider the feedback. Evaluation positivity also influenced self-efficacy. Beliefs about and use of Ratemyprofessors.com were not related to student gender, college class, or age. Evaluation positivity's effect on student course decision making and self-efficacy has implications for for university students, faculty, and administrators.