Today, many organizations see the value of developing their employees through learning partnerships. Recognizing that every person is a complex combination of psychological and physiological components, and that the specific details of effective mentoring relationships will be as individual as the people involved in the learning partnership, the purpose of this study was to determine if there was a correlation between mentor Psychological Type (based on the Myers-Briggs Type Inventory) and mentor competency (based on the Principles of Adult Mentoring Inventory) in the six mentor behavioral functions defined by Cohen: Trust, Advice, Alternatives, Challenge, Motivation, and Initiative. This research used a causal-comparative study to examine if differences in mentor psychological type were related to mentor competency in Cohen's six mentor behavioral functions. Results from this research indicated no relationship between mentor psychological type and mentor competency. While the research data did not indicate the expected relationship between psychological type and mentor competence it did support the fundamental elements of psychological type theory. Individuals are exactly that unique. Effective mentors recognize the complexity of human learning, respect unique protégé requirements in the learning process, and are self-aware. Recommended areas for further analysis included analysis of individual components of psychological type and mentor competency; dominant Jungian mental function and mentor competency; including information gathered from a 360-degree feedback instrument, and exploring the possibility of a relationship between successful mentoring relationships and locus of control and locus of responsibility.