OBJECTIVE Two main generational cohorts comprising students enrolled in medical schools today are Generation Xers (born 1965-1980) and Millennial students (born 1981-1999). A subset is Cuspars (born 1975-1980), who share traits with both generations. Population theorists ascribe different personal characteristics, attitudes, and preferences to each group. The authors examined whether selected characteristics describing Generation X and Millennial students were quantifiable using a personality measure. Differences among Generation X, Millennial, and Cuspar medical students were investigated. METHODS Eight hundred and nine medical students (399 females and 410 males) who matriculated between 1989-94 and 2001-04 at the Northeastern Ohio Universities College of Medicine completed the 16 Personality Factor Questionnaire (16PF). Differences in responses to the 16PF among the three generations were analyzed using multivariate analysis of variance (MANOVA). RESULTS Analyses showed significant differences for Generation X versus Millennial students on 10 of the 16 personality factors. Millennial students scored significantly higher than Generation X students on factors including Rule-Consciousness, Emotional Stability, and Perfectionism; Generation X students scored higher than Millennials on Self-Reliance. Millennials also were significantly different from Generation Xers on several other factors. Significant differences were noted among Cuspars, Generation Xers, and Millennials. CONCLUSIONS The 16PF is a useful tool to examine differences among these groups and to help understand the factors that constitute their personalities. Given differences among the generational groups, the authors forecast possible educational implications for medical school academic affairs and student services, and suggest areas for future research.