The relationship between posttraumatic stress disorder (PTSD) and asthma in the wake of natural disasters is poorly understood. Using pre- and postdisaster data (N = 405) from the Resilience in Survivors of Katrina (RISK) project, we examined associations between PTSD symptoms, measured by the Impact of Event Scale-Revised (IES-R), and self-reported postdisaster asthma attacks. A 1-point increase in the IES-R avoidance score, which corresponded to one standard deviation change in this sample, was associated with double the odds of reporting an asthma attack or episode since the hurricane, 95% CI Revise spacing among characters: [1.22, 4.16]. Association with hyperarousal and intrusion symptoms was null. Further research using objective measures of asthma morbidity is needed; nevertheless, these findings may help inform postdisaster health services delivery and predisaster mitigation planning.