BACKGROUND: The knowledge of scientific dishonesty is scarce and heterogeneous. Therefore this study investigates the experiences with and the attitudes towards various forms of scientific dishonesty among PhD-students at the medical faculties of all Norwegian universities. METHOD: Anonymous questionnaire distributed to all post graduate students attending introductory PhD-courses at all medical faculties in Norway in 2010/2011. Descriptive statistics. RESULTS: 189 of 262 questionnaires were returned (72.1%). 65% of the respondents had not, during the last year, heard or read about researchers who committed scientific dishonesty. One respondent had experienced pressure to fabricate and to falsify data, and one had experienced pressure to plagiarize data. On average 60% of the respondents were uncertain whether their department had a written policy concerning scientific conduct. About 11% of the respondents had experienced unethical pressure concerning the order of authors during the last 12 months. 10% did not find it inappropriate to report experimental data without having conducted the experiment and 38% did not find it inappropriate to try a variety of different methods of analysis to find a statistically significant result. 13% agreed that it is acceptable to selectively omit contradictory results to expedite publication and 10% found it acceptable to falsify or fabricate data to expedite publication, if they were confident of their findings. 79% agreed that they would be willing to report misconduct to a responsible official. CONCLUSION: Although there is less scientific dishonesty reported in Norway than in other countries, dishonesty is not unknown to doctoral students. Some forms of scientific misconduct are considered to be acceptable by a significant minority. There was little awareness of relevant policies for scientific conduct, but a high level of willingness to report misconduct.