Implicit biases can foster negative attitudes and lead to damaging stereotypical behaviors. Stereotypes can negatively affect the education, hiring, promotion, and retention of women in science, technology, engineering, and mathematics (STEM). This study evaluated the impact of diversity training on university faculty (N=234) by assessing changes in implicit associations and explicit attitudes toward women in STEM. Personal implicit associations about women in STEM improved for men, but not for women who already tended toward more positive implicit associations at pre-test. Men were more likely than women to explicitly endorse stereotypes about women in STEM at both pre- and post-test, and these attitudes did not change as a result of the diversity training. These findings suggest that participation in a brief diversity training can improve implicit associations about women in STEM.