Purpose. Nursing has evolved as a unique and independent field over the last decades. Unfortunately, many nurses in Korea express concern that they lack appropriate background knowledge in bioscience necessary to practice nursing competently. To determine the reasons of their concerns, we examined the perceptions of RNs regarding bioscience courses in their undergraduate (Baccalaureate and 3 year diploma program) and their perceived relations to the practice of nursing. Methods. The structured questionnaires were sent to 3 university-affiliated tertiary hospitals in Seoul, Korea. Results. The responses given by the nurses in the two groups were similar. The nurses in this study reported that the bioscience courses they took as undergraduates had little relation to their professional tasks. This lack of link between bioscientific knowledge and nursing practice may be partly due to the fact that the courses are taught by non-nursing faculties who are not familiar with nursing tices. It also appears that bioscience knowledge deficit was most prominent during nursing assessment regardless of the program they attended or the unit they are currently working. Conclusion. Bioscience courses should be integrated into the nursing curriculum properly and taught by nursing faculty who have a strong background in biological sciences.