Introduction: In John Holland's theory of vocational personalities and work environments, the hexagonal model organizes personal and occupational data, and serves to define the degree of consistency in a personality or job environment configuration, as well as the degree of congruence between a person and their environment. The objective of the present study was to analyze the structural validity of Holland's hexagonal model and Gati's hierarchical model in a sample of 636 Mexican high school students, using scores from the Self-Directed Search (SDS). Method: To analyze model fit, we used the randomization test of hypothesized order relations (RTOR) and non-metric multidimensional scaling (MDS). Results: The Social personality type presented the highest mean score, followed by the Enterprising type and then the Artistic and Investigative. The lowest mean scores were seen in the Realistic and Conventional types. In relation to the internal consistency, Cronbach's alpha coefficients were acceptable (.765) to good (.845). The results of the RTOR test indicated that Holland's model showed moderate, significant fit (CI=0.65) to the observed data, and Gati's model showed high fit (CI=0.778). The MDS solution for the total sample (Stress =0.01; RSQ =0.99) showed that the types were distributed according to the RIASEC order, but their spatial arrangment was a misshapen polygon, with the Investigative type located toward the center of the circle. The analysis of fit by gender and school year did not reveal significant differences (p>0.05), although there was a higher level of fit with students in their final year than with students in previous grades. Discussion and conclusions: These results provide empirical evidence of the structural validity of Holland's and Gati's RIASEC models in this student sample. These models can be considered an adequate representation of the vocational interests of these students. The results also provide evidence of construct validity of the SDS scores, which has practical implications for the utility of this instrument in vocational and career guidance.