The Personal Style Inventory was designed to assess Jungian personality types. The present study determined its reliability and validity. The Myers-Briggs Type Indicator was used as a criterion and the multitrait-multimethod matrix method was used to assess reliability and validity. Reliability coefficients between the opposite sides of each scale were —1.00 and validity coefficients between corresponding scales of the Personal Style Inventory and the Myers-Briggs Type Indicator ranged between .52 and .70. The lowest validity coefficients were with Extraversion-Introversion scales. Significant differences between validity coefficients were also found between participants' congruent and incongruent scores on the Extraversion-Introversion and Judgment-Perception scales. The results suggest feasibility of using the Personal Style Inventory to assess Jung's personality types.