Occupational injuries are a public health problem, estimated to kill more than 300,000 workers worldwide every year and to cause many more cases of disability. We estimate the global burden of fatal and non-fatal unintentional occupational injuries for the year 2000. The economically active population (EAP) of about 2.9 billion workers was used as a surrogate of the population at risk for occupational injuries. Occupational unintentional injury fatality rates for insured workers, by country, were used to estimate WHO regional rates. These were applied to regional EAP to estimate the number of deaths. In addition to mortality, the disability-adjusted life years (DALYs) lost, which measure both morbidity and mortality, were calculated for 14 WHO regions. Worldwide, hazardous conditions in the workplace were responsible for a minimum of 312,000 fatal unintentional occupational injuries. Together, fatal and non-fatal occupational injuries resulted in about 10.5 million DALYs; that is, about 3.5 years of healthy life are lost per 1,000 workers every year globally. Occupational risk factors are responsible for 8.8% of the global burden of mortality due to unintentional injuries and 8.1% of DALYs due to this outcome. Occupational injuries constitute a substantial global burden. However, our findings greatly underestimate the impact of occupational risk factors leading to injuries in the overall burden of disease. Our estimates could not include intentional injuries at work, or commuting injuries, due to lack of global data. Additional factors contributing to grave underestimation of occupational injuries include limited insurance coverage of workers and substantial under-reporting of fatal injuries in record-keeping systems globally. About 113,000 deaths were probably missed in our analyses due to under-reporting alone. It is clear that known prevention strategies need to be implemented widely to diminish the avoidable burden of injuries in the workplace.