The purpose of the study was to explore the influence of family characteristics (family function and parental authority styles) and core self-evaluations (CSE), in adolescents' career formation. Drawing on the relational framework of Cutrona and Russell, the study examined the mediating role of CSE on the relationship between family and parental variables and adolescents' career decision-making (CDM) difficulties. Using a sample of 289 Greek students, it was found that for male students the permissive and authoritarian parenting styles and the family cohesion contributed significantly to the prediction of CDM difficulties. Males' decision-making difficulties were not influenced by CSE. Females' decision-making difficulties were influenced negatively only by the parents' authoritarian style. Contrary to males, CSE fully mediated the relationship between the authoritarian style and females' decision-making difficulties. The specific findings are discussed in reference to gender differences in adolescents' personality development. Implications for research and adolescents' career counseling are also discussed. (Contains 2 notes, 4 tables, and 1 figure.)