Purpose: The purposes of this study were to investigate the posttraumatic growth, a positive mental and psychological change and related factors experienced by firefighters, in order to prevent PTSD and to for use as basic data for mental health promotion. Methods: This study was a descriptive research study with 186 firefighters working in two fire stations in Busan Metropolitan City. It was conducted from August 1 to 31, 2015. There were 5 research tools in the structured survey, including IES-R-K, Resilience Scale, FACES-III, OCQ, and K-PTGI. Collected data were analyzed with t-test, ANOVA, Pearson correlation coefficients and multiple linear regression analysis using SPSS/WIN 18.0. Results: The related factors affecting posttraumatic growth in firefighers were family cohesion (β =.15, p=.044), organizational commitment (β=.61, p<.001), gender (β=.16, p=.023) and amount of work experience in the current field (β=.28, p=.001). The explanatory power of these factors for posttraumatic growth was 43.1%. Conclusion: The results indicate a need to develop and distribute intervention programs that focus on strengthening the resilience of individuals, organizational commitment and family cohesion to promote post-traumatic growth, instead of focusing on crisis intervention and follow-up programs after traumatic experiences.