The Health Promotion Model (HPM) was tested as a causal model to predict workers' use of hearing protection (N = 645). Measures indicated an excellent fit of the theoretical model. The exploratory analyses found the same cognitive-perceptual factors most important in predicting use. However, in contrast to the theoretical model, two modifying factors (job category and situational factors) had direct effects on use. The hypothesized model accounted for 49.3% of variance and the exploratory models accounted for 50.7% to 52.7% of variance in hearing protection use. Results of testing the HPM are consistent with the recently proposed revision of the model by Pender, Walker, Frank-Stromborg, and Sechrist (1990a, 1990b). The strongest effects on behavior came from the behavior-specific influences and demographic characteristics. Situational factors had a direct effect on the health behavior.