PURPOSE: To present residents' personal observations of unethical and unprofessional conduct in medicine during their first year of training. METHOD: Eight hundred and fifty-seven second-year residents who had previously participated in a study of perceived mistreatment as senior medical students were resurveyed by a three-tiered mail process concerning their experiences during their first postgraduate year, including their personal observations of four types of unethical and unprofessional conduct. RESULTS: Surveys were returned by 571 residents, for a response rate of 67%. Personal observations of falsification of patient records by others on at least one occasion were reported by 44.5% of the responding residents, while 73.8% reported direct observations of mistreatment of patients. Nearly half of the residents (46.7%) reported that others had taken credit for their work, and 72.8% said they had observed colleagues working in an impaired condition at least once during their first year of training. Over one fourth of the residents (28.6%) stated that they had been required to do something during the year that they believed was immoral, unethical, or personally unacceptable. There was an inverse relationship between the residents' observations of unethical and unprofessional conduct and their overall satisfaction with their first year of training (p < .001). CONCLUSIONS: The residents reported observing several types of unethical and unprofessional conduct among their colleagues and superiors. These findings confirm similar reports among medical students and residents and raise questions about the possible effect of such observations on the ethical principles and behavior of physicians-in-training.