The purpose of this research was to identify the self-reported factors affecting the career decision making of Mexican and Mexican-American students. It was hypothesized that the factor clusters would differ between the two sample populations, Mexican and Mexican-American. It was also hypothesized that these clusters would differ from six clusters identified by O'Neil et al. (1980) in their Midwestern United States sample. The total sample of 380 students was representative of Mexican-American students attending high school in Douglas, Arizona, as well as college preparatory students from Cuidad Obregon, Sonora, Mexico. Teachers in both locations administered the Career Factor Checklist (CFC) to the students in their classrooms. The CFC includes 28 items divided into the O'Neil scales and representative of the following factors: familial, societal, individual, socioeconomic, situational, and psychosocial-emotional. The factors were analyzed using the Statistical Package for the Social Sciences (SPSS) program. Varimax rotation procedures were used to identify simple structure and factor invariance. Results showed different factors influencing the vocational aspirations of the two sample populations. It also appeared that these factors differed, especially for Mexican students, from those identified by O'Neil et al. The differences between the Mexican and Mexican-American students' responses may be due to acculturation. Counselors should consider both personality and environmental factors when working with these students. (TES)