This study was conducted to compare women’s and men’s retrospective perceptions of the mentoring they received during their training and career development in chemistry. Participants were 455 graduates (135 women) who received doctoral degrees from 11 top US chemistry programs over a 5-year period (1988–1992). In 2003, graduates completed surveys of undergraduate, graduate, post-doctoral, and initial employment experiences. In line with Social Cognitive Career Theory (Lent et al., Journal of Vocational Behavior 45:79–122, 1994), which posits that perceptions of barriers can affect career decisions, results suggest that women perceived that they received less mentoring than men at the undergraduate, graduate, and post-doctoral levels of training, likely related to gender differences in eventual career success. Possible interventions at the individual and institutional levels are discussed.