The purpose of this study was to examine how an undergraduate family diversity course supported students to enhance undergraduate students' understanding of diversity issues and cultural competence that are necessary to work with diverse families and children as future family science professionals. We collected qualitative research data from 108 students who were enrolled in five sections of an undergraduate-level diversity course, Working with Diverse Families and Children, using nine open-ended questions. In the current study, we specifically focused on four questions in relevant to what undergraduate students learned and what they desired to learn more about diversity issues in families grounded in Hollinger's developmental model of ethical reflection. Using inductive and deductive iterative processes and triangulation, we conducted thematic analysis. Overall, our findings showed that undergraduate students understood the core concepts of diversity and cultural competence. However, they understood these issues at different stages of Hollinger's model of ethical reflection after taking the course. Most undergraduate students accomplished their cognitive and empathetic understanding of diversity and were primarily in Stages 1 and 2. We suggest interactive and reflective teaching strategies that may be effective for undergraduate students to challenge their own biases, practice ethical decision, and prepare for social actions as family science professionals.