Background and Objective: Bioethics is a multidisciplinary subject which has been of major significance to biotechnology researchers and related fields. The aim of this survey was to assess knowledge and attitudes of postgraduate students of Medical Faculty regarding bioethical issues.Materials and Methods: This cross-sectional study was carried out among the postgraduate basic medical sciences students of Faculty of Medicine in Mashhad University of Medical Sciences, Mashhad, Iran. A selfadministered questionnaire consisted of 42 questions was designed to assess knowledge and attitudes of postgraduate students on bioethical issues.Results: A total of 107 postgraduate students (out of 114), including 73 Master (MSc) and 34 Doctoral (PhD) students filled out the survey (93.8%). Only 17.6% of PhD students had a good knowledge of bioethics whereas none of the MSc students fell within this category. On average almost 68.5%of the respondents were familiar with the term "Bioethics". About 95.7% of MSc students reported that no academic courses were offered in bioethics whereas 54.5% of PhD students were able to take academic courses in the field. The results also showed that about 85 % of the respondents generally believed that it was necessary to increase their knowledge of bioethics.Conclusion: Although the postgraduate students were familiar with the term “Bioethics”, their awareness about bioethical issues was not very desirable. Results showed that the students had a high level of motivation for increasing their general knowledge in the field, so the necessity of designing appropriate courses on bioethics in university curricula should be reinforced.