Background: Schools are increasingly being called upon to address cyberbullying and its consequences. This study compares cyberbullying and school bullying trends and examines help-seeking among cyberbullying victims. Methods: We analyzed self-report data over 4 surveys (2006-2012) from more than 16,000 students in 17 MetroWest Boston high schools. Using generalized estimating equations, we examined school and cyberbullying victimization trends by sex, grade, and sexual orientation. Results: From 2006 to 2012, cyberbullying increased from 15% to 21% (p?<?0.001). In 2006, school bullying was 1.7 times higher than cyberbullying (26% versus 15%); by 2012, school bullying and cyberbullying were similar (23% versus 21%). Cyberbullying increased more among girls (17% to 27%; p?<?0.001) than boys (12% to 15%; p?<?0.001). There was no net increase in school bullying among girls (26% in 2006 and 2012) and a decrease among boys (25% to 18%; p?<?0.001). Sexual minorities were more likely than heterosexuals to be bullied at school and online at every survey. Only 33% of cyberbullying victims told an adult; more victims told parents/non-school adults (29%) than school adults (17%). Conclusions: Despite decreases in school bullying, cyberbullying rose steadily, particularly among girls. Increased attention to sociodemographic differences in bullying could promote help-seeking and positive online behavior.