Community characteristics, such as perceived collective efficacy, a measure of community strength, can affect mental health outcomes following disasters. We examined the association of perceived collective efficacy with posttraumatic stress disorder (PTSD) and frequent mental distress (14 or more mentally unhealthy days in the past month) following exposure to the 2004 and 2005 hurricane seasons.Participants were 1486 Florida Department of Health workers who completed anonymous questionnaires that were distributed electronically 9 months after the 2005 hurricane season. Participant ages ranged from 20 to 79 years (mean, 48; SD, 10.7), and the majority were female (79%), white (75%), and currently married (64%). Fifty percent had a BA/BS degree or higher.In 2 separate logistic regression models, each adjusted for individual sociodemographics, community socioeconomic characteristics, individual injury/damage, and community storm damage, lower perceived collective efficacy was significantly associated with a greater likelihood of having PTSD (OR, 0.93; 95% CI, 0.90-0.96), and lower collective efficacy was significantly associated with frequent mental distress (OR, 0.94; 95% CI, 0.92-0.96).Programs enhancing community collective efficacy may be a significant part of prevention practices and possibly lead to a reduction in the rate of PTSD and persistent distress postdisaster. (Disaster Med Public Health Preparedness. 2019;13:44-52).