The main objective of the study was to analyze the differences between samples from general and clinical sample in personality prototypes (PRP), derived from the Millon Adolescent Clinical Inventory (MACI). The methodology included an analytical and observational design with a random, multi-stage, stratified and proportional cluster sampling in general sample (n= 461) and consecutive sampling of clinical sample (n= 219), in adolescents between 13 and 17 years of age. We found introvert, inhibited, doleful, forceful, oppositional, self-demeaning and borderline PRP in the clinical sample and dramatizing and conforming PRP in the general sample present a significantly higher mean. There is a relevant absence of significant differences in egotistic, submissive and unruly PRP. By sex, more significant differences in PRP are observed in the clinical sample. By age, a significant downward linear trend in the submissive and conforming PRP is observed, as well as an upward trend in the unruly and forceful PRP in the general sample. The clinician must be alert in the interpretation of the MACI PRP that do not differentiate between general and clinical samples.