Self-to-prototype matching is a strategy of mental comparisons between the self-concept and the typical or “representative” member of a group to make some judgment. Such a process might contribute to interest in pursuing a science career and, relatedly, women’s underrepresentation in physical science, technology, engineering, and mathematics (pSTEM) fields. Across four studies, we measured self–scientist discrepancies on communal, agentic, and scientific dimensions, and assessed participants’ interest in a science career. The most consistent predictor of science interest was the discrepancy between self and scientist on the scientific dimension (e.g., intelligent, meticulous). Study 4 established that students with larger self–scientist discrepancies also had less accurate perceptions of students pursuing science, and that inaccuracy was related to lower science interest. Thus, students with lower science interest do not just perceive scientists differently from themselves but also erroneously. Discrepancy and inaccuracy together explained a significant portion of the gender gap in pSTEM interest.