As racial and ethnic diversity increase in the U.S., genetic counselor multicultural competence is growing in importance. In mental health counseling, supervisor multicultural competence has been shown to promote supervisees' multicultural competence. Moreover, developmentally-advanced supervisors tend to be more effective. This study was designed to investigate relationships among genetic counselor supervisors' perceived multicultural counseling competence and development as supervisors, and their ability to evaluate a supervisee's multicultural skills. One hundred twenty-two supervisors completed an online survey of demographics, the Multicultural Counseling Knowledge and Awareness Scale, the Supervisor Development Scale, and a hypothetical vignette in which they evaluated a supervisee's multicultural skills and provided written feedback. Stepwise multiple regression yielded five significant predictors accounting for 31% of the variance in accuracy of supervisor evaluations of the student: multicultural awareness, multicultural knowledge, age, supervision experience, and supervisor development. Six feedback themes were identified from written responses. Practice and research suggestions are provided.