Holland's Vocational Preference Inventory (VPI) and Super and Forrest's Career Development Inventory (CDI) are recommended in the their respective manuals for use with secondary school students regardless of academic ability. Scores on both instruments for 245 suburban high school seniors in this investigation were well below reported means. Canonical correlation and discriminant function analyses confirmed that students scoring higher on the CDI preferred a broader range of occupations on the CPI, and that both instruments may be overly dependent on academic ability. Despite independent theoretical and methodological roots, the VPI and CDI appear to be significantly related to each other and to grade point averages among high school seniors. Academic achievement bias may artifically depress scores for students likely to prefer jobs less dependent on reading ability and vocabulary skills implicit in these instruments. These findings also suggest that there may be threshold of vocational maturity, as measured by the CDI, below which students are not sufficiently interested in or informed about occupational choices to consider the range of job titles in the VPI. (Author)