Background Despite the implementation of codes and declarations of medical research ethics, unethical behavior is still reported among researchers. Most of the medical faculties have included topics related to medical research ethics and developed ethical committees; yet, in some cases, unethical behaviors are still observed, and many obstacles are still conferring to applying these guidelines. Methods This cross-sectional questionnaire-based study was conducted by interviewing randomly selected 331 Lebanese physicians across Lebanon, to assess their awareness, knowledge and attitudes on practice regarding (...) international and national research ethics guidelines and scientific misconduct and misbehaviors. Results Our results revealed that although majority of participants declared familiar with ethical principles governing research that involves human subjects, the overall mean score achieved on their knowledge questions was 46%. Only 27.4% are aware of the presence of the Lebanese National Consultative Committee on Ethics, with only half of them aware of its functions and only 25.7% know about the charter of ethics and guiding principles of scientific research in Lebanon. Significant higher levels of research ethics knowledge were recorded among Ph.D. degree-holding subjects, higher university positions as in professors, research ethics trainings-attendees, and physicians with prior research experience. A significant correlation was observed between knowledge of research ethics principles and positive attitudes toward research ethics principles. Noteworthy, we found that more than one third of participants have reported witnessing scientific misconduct and misbehaviors at some period of their careers. Conclusions The presence of low mean awareness levels regarding research ethical principles among the study population of physicians and high levels of perception of scientific misconduct raises concern on the importance of implementing proper training for physicians on research ethics. (shrink)