As part of Shell's health surveillance program, morbidity frequency and severity by smoking status (current smoker, exsmoker, nonsmoker) were compared for the 3-year period 1985 through 1987. Morbidity data for this study were extracted from the morbidity section of the Shell Health Surveillance System, which included all illness and absence events in excess of 5 days. Statistically significant positive associations were seen between smoking habits and overall morbidity, diseases of the circulatory system, and diseases of the respiratory system for both male and female employees. In addition, a significantly increased association between smoking and both non-motor vehicle accidents and motor vehicle accidents among current smokers was noted. Current smokers had a greater than 60% higher frequency rate (P less than .05) for non-motor vehicle accidents than nonsmokers for both men and women. Male smokers also had a 75% increased (P less than .05) motor vehicle accident rate. These results suggest that it may be possible to reduce overall illness and injury morbidity through implementation of successful smoking cessation programs.