During the period 1986-92, a questionnaire survey was conducted among research project administrators whose study protocols were assessed by the ethical committee for biomedical research in Health region 4 (Central Norway). The questions referred to the scientists' attitudes towards medical research ethics in general, and their views on the work of the committee. They were also asked to comment on seven statements about scientific fraud and misconduct. This paper presents data on misconduct from the 119 scientists who completed the questionnaire, i.e 70% of the 159 recipients. Some 40% claimed that scientific fraud is a problem in Norway, but 46% maintained that it is less so than in other countries. More than every fourth researcher (27%) knew of one or more cases of scientific misconduct, 42% stated that their knowledge was not publicly known. 18% felt that they had been exposed to misconduct themselves. A majority (60%) stated that a better system is needed to investigate claims of scientific fraud. The authors discuss these findings in relation to the personal characteristics and scientific qualifications of the researchers, and the current knowledge about the extent of scientific fraud in medicine.