Basic first-aid skills can be useful in treating minor injuries that commonly result from natural disasters in the United States. Yet there has been insufficient research on training and competence in first-aid skills among community residents. This study utilises panel data for 414 adults in Los Angeles, California, who were interviewed within three years of the 1994 Northridge earthquake and re-interviewed in 1999 after the El Ninõ winter of 1997-98. Descriptive, bivariate and multivariate analyses were performed. Results showed that 24 percent of the members of the sample had received first-aid training since their Northridge earthquake interview. First-aid training, particularly recent training, was associated with greater perceived first-aid skills, as well as with increased expected and actual employment of those skills. With the appropriate training and skill retention, lay members of the public can potentially contribute to a post-disaster medical response.