OBJECTIVE: Occupational injury and illness rates for volunteer responders have not been well documented. We analyzed data specific to volunteers from the American Red Cross (ARC). METHODS: Data collected by the ARC between 2008 and 2012 were analyzed to identify disaster factors associated with responder injuries and illnesses. We focused on disaster-relief operation (DRO) level (indicating operational costs, ranging from 3 [lower] to 5+ [higher]); disaster type; region; and year. We calculated injury and illness rates and estimated rate ratios (RR) with 95% CI, using negative binomial regression. Also, we analyzed a total of 113 disasters. RESULTS: Hurricanes had the highest rates of injuries (14/1000 responders) and illnesses (18/1000 responders). In the adjusted model for injuries, RRs were higher for DRO levels 4 (3.6 [CI, 2.0-6.7]) and 5+ (4.9 [CI, 2.2-11.0]) than for level 3. In the adjusted model for illnesses, RRs also were higher for DRO levels 4 (4.4 [CI, 2.6-7.3]) and 5+ (8.6 [CI, 4.1-17.7]) than for level 3. CONCLUSIONS: Higher DRO levels were a significant predictor of greater rates of occupational injuries and illnesses. Careful selection of responders, including volunteers, has been warranted for deployments to such disasters. (Disaster Med Public Health Preparedness. 2014;0:1-7).