We examine the extent to which career mentoring and psychosocial mentoring received from their advisors relates to advisee perceptions of advisor-advisee relational uncertainty. Doctoral students (N = 378) completed the "Academic Mentoring Behaviors Scale" (Schrodt, Cawyer, & Sanders, 2003), the "Mentoring and Communication Support Scale" (Hill, Bahniuk, Dobos, & Rouner, 1989), and the "Relational Uncertainty Scale" (Knobloch & Solomon, 1999). The results of a series of Pearson correlational analyses indicate that advisees' reports of received career mentoring and psychosocial mentoring from their advisors are negatively related to their advisor-advisee relational uncertainty. These findings emphasize further the importance of advisors' provision of mentoring support for their advisees.