Hysteria described for more than 600 years in a variety of cultures and settings for significant adverse of public health consequences and economic implications. The aim of this study was to investigate the outbreak, determine possible risk factors and guide intervention measures. In December 25, 2012, district health office notified to Regional Health Bureau about a suspected hysteria outbreak at Kombolcha General primary school. We investigated all 50 cases and compared with 100 matched controls. For the study, detailed discussions were also undertaken with school principal, teachers, students' parents, district health officers and administrators about the event. Then data was analyzed using Epi Info version 7. Fifty cases and no death were identified. The mean age of all cases and controls was 13 with a range 9-16 year. All were girls, and mostly friends (75%). The overall attack rate of the cases were 32 per 1000 populations in all age group. Using multivariate analysis, illness were remained as risk factors, perceive evil devil force (Adjusted Odds Ratio (AOR) 5.3 with 95% CI 2.3-12), psycho stress (AOR) 2.6, 95% CI 1.14-5.72) and seeing the affected students (AOR) 2.9; 95% CI 1.1-7.78). Knowledge of modes of transmission illness (AOR) 0.48, 95% CI 0.24-0.96) and separation of girls from the environment at least for 1-2 weeks (AOR) 0.49, (95% CI 0.22-0.98) were remained as protective factors for the illness. The study confirmed the hysteria outbreak in Kombolcha Town of school girls at General Primary school. And threatening situation was associated with a socio-cultural belief with psycho stress. We recommended conducting immediate reassurance, separate therapy, create community awareness about the illness and counseling at the school could be possible to manage events.