Vocational identity is an important construct for physician career development. Physician vocational development has been grouped into three tasks (crystallization, specification, and implementation) pertaining to career choice and specialty choice (1) In defining the construct of vocational identity, it has been suggested that the relation between vocational behavior and personality be examined (2) To better understand the vocational development tasks of physicians and to learn about its relation to personality, the present study sought to examine personality factors of medical students who exhibit different career choice patterns based on vocational development tasks. It tested the hypothesis that medical students with different career choice patterns were significantly different with regard to personality. This study compared personality factors of four groups of 155 first-year medical students who exhibited different career choice patterns based on the results of the Medical Career Development Inventory (MCDI). The MCDI and the Sixteen Personality Factor Questionnaire (16PF) were group administered to entering medical students during orientation. Discriminant analysis determined the extent to which the four career pattern groups could be differentiated by the set of 16PF scores. Results showed that the personality factors of Social Boldness (Wilks' [lambda]=0.825, X2=29.00, p is less than 0.000) and Tension (Wilks' [lambda]=0.927, X2=11.48, p is less than 0.003) predicted differences between the groups. Specifically, medical students who had neither crystallized nor specified a career preference were less thick-skinned and socially bold than participants who had coped with one or both of the tasks. Additionally, medical students who had coped with the task of career crystallization, or who neither crystallized nor specified a career preference, were more tense, impatient and driven than participants who had coped with career specification or who had coped with both tasks. The findings of this study may provide information helpful in identifying students, based on certain personality characteristics, who are struggling with the vocational development tasks associated with becoming physicians. Appropriate interventions may then be designed and implemented by medical school advisors, counselors, and educators to assist medical students.