This study compared hospital-admitted injuries during the 14 days after the Northridge, California, earthquake of January 17, 1994, with hospital-admitted injuries during the preceding 16 days at the same facilities. Seventy-eight hospitals providing emergency care in Los Angeles County were screened; 16 were identified as having admitted at least one person for an earthquake-related injury. Retrospective chart reviews of hospitalized injuries for all of January 1994 were conducted at those facilities. The Northridge earthquake resulted in 138 injuries severe enough to require hospitalization. On the day of the earthquake, such injuries were 74% more frequent than usual overall. Some hospitals experienced as many as five times the number of injury admissions seen in the days preceding the event. The increase in caseload was short-lived, however; injury admissions tended to return to normal levels within two days after the quake. Previous reported estimates of the overall number of severe injuries caused by the Northridge earthquake appear to be exaggerated. (Am J Emerg Med 2000;18:361-366. Copyright © 2000 by W.B. Saunders Company)