In 2008, the US Congress reported on the Hidden Tragedy the underreporting of occupational injuries. Two national surveillance systems capture data on nonfatal occupational injuries in the USA. The National Institute for Occupational Safety and Health (NIOSH) collects data on nonfatal occupational injuries treated in emergency departments (ED) by using indirect identification of work-relatedness by workers at the time of treatment. The Bureau of Labour Statistics (BLS) collects similar nonfatal injury data but as reported by private industry employers. The ED data suggest that from 1998 to 2007 occupational injuries occurred at a relatively constant level (about 3.4 million/year and a rate of about 3 injuries/100 fulltime workers) among workers in all industries. In contrast, the employer-based reporting for private industry suggests that there was a marked decline in injuries for the 10 year period (from 5.9 million at a rate of 6.7/100 full-time workers in 1998 to 4.0 million at a rate of 4.2/100 full-time workers in 2007). The complexities of the case definitions, sample designs and specific worker populations included, make comparing the two systems difficult. However, the ED worker-based reporting data suggest that the apparent decrease in injuries over the 10 year period indicated by employer based reporting may have been significantly influenced by increases in underreporting during recent years. Studies are currently underway by NIOSH and BLS to examine incentives and disincentives to reporting by workers and employers.