We examined teacher characteristics predicting likelihood of intervening in indirect bullying (N=55) and piloted a 45-minute educational presentation about its mental health impact. Teachers' global empathy and perceived seriousness of indirect bullying vignettes were predictors of their likelihood of intervening, but knowledge of mental health impact was not. The presentation increased knowledge of impact and perceived seriousness, immediately and seven weeks later, compared with a treated control group. However, empathy for victims and likelihood of intervening did not increase. Recommendations include adding skills-based material, a self-efficacy measure and a focus on increasing global empathy rather than specific empathy for victims. (Contains 1 figure and 5 tables.)