The present study applied Ajzen's (1985) theory of planned behavior to the explanation of ethical decision making. Nurses in three hospitals were provided with scenarios that depicted inadequate patient care and asked if they would report health professionals responsible for the situation. Study results suggest that the theory of planned behavior can explain a significant amount of variation in the intent to report a colleague. Attitude toward performing the behavior explained a large portion of the variance; subjective norms explained a (...) moderate amount of the variance; and, perceived behavioral control added little to the explanation of variance. Implications for research and practice are discussed. (shrink)