A study of emergency medical service (EMS) response to traumatic injuries and medical emergencies occurring at West Virginia worksites was conducted. Computerized data for EMS team responses to 5836 job sites in West Virginia during the period July 1, 1984 to June 30, 1986 were examined to assess the timeliness of the responses. Of the emergencies responded to, 1874 were medical problems such as acute illness, chest pain, or breathlessness, 3339 were injuries, and 623 were classified as other. A total of 1736 injuries were due to mining accidents. The remaining injuries were due to non mining accidents. The mean times for responding to the medical problems, nonmining injuries, and mining injuries were 9.1, 11.6, and 20.0 minutes, respectively. Sixty three of the response times were equal to or less than 8 minutes, the benchmark for a timely response. The mean number of response miles traveled was 5.8, 6.9, and 10.7 for the runs for medical problems and non mining and mining injuries, respectively. After 60 minutes, considered to be the benchmark for timely transport, 86 percent of the patients with medical problems and 78 percent of those with non mining injuries had been transported to a hospital; however, only 45 percent of the patients with mining injuries had reached hospital emergency rooms. The authors conclude that EMS response times for medical problems and non mining injuries are significantly better than those for mining injuries. Many jobsites in West Virginia do not have EMS response times of 8 minutes or less. Upgrading the training of emergency medical personnel in mines and keeping an emergency vehicle at mines may help improve the emergency response to mining accidents.