Using compensation records of the National Labor Insurance, this study estimates workers?incidence rates of injury or illness, disability, and mortality from occupational or non-occupational causes for 1994 and 1996, the year prior to and the year post the effectiveness of the National Health Insurance, respectively. The purpose is to assess changes in these rates and to propose implications related to those changes. The number of workers covered by the Labor Insurance decreased by some one million or 1 2.5% after the national health insurance program became effective in March 1995. While the rate of overall occupational injury increased slightly from 3.97/103 in 1994 to 4.26/103 in 1996, rate of overall non-occupational injury, on the other hand, declined dramatically from 31.37/103 to 21.20/103, respectively, largely due to a substantial reduction of non-occupation-related diseases. The results may lead to two implications. Firstly, the increase of occupational injury might be associated with the subs tantial dropout of people who were not 烒eal?workers but covered in the system leading to a reduced population size of workers actually at potential risk of occupational injury. Secondly, a remarkable decrease in risk of non-occupation-related diseases may lead to a speculation that the labor-insured workers were relatively healthier in 1996 than in 1994. Our findings call for a particular caution to use the labor health compensation records documented before and after 1995. Future studies should be de voted to merge data from both compensation records and national health insurance registry for the attainment of accurate estimation of incidence rate and severity of workers' injuries in Taiwan.