BACKGROUND: Cardiopulmonary resuscitation (CPR) is a life-saving technique which is used after cardiopulmonary arrest. Chance of survival after arrest will increase if it is coupled with sufficient knowledge. Final year undergraduate health science students and interns manage many trauma and critically ill patients in our hospital. Even though all students took CPR training in undergraduate course, we sometimes saw difficulties in the resuscitation of patients after cardiopulmonary arrest by undergraduate health professionals. This study was to assess the level of knowledge of undergraduate health science students and medical interns about cardiopulmonary resuscitation. METHODS: Hospital based cross-sectional study was conducted from February 1 to March 30, 2013. All undergraduate health professionals were included. The mean score of knowledge was compared for sex, original residence and department of the participants by using Student's t test and ANOVA with Scheffe's test. P values <0.05 were considered statistically signifi cant. RESULTS: Four hundred sixty-one out of 506 students were included in this study with a response rate of 91.1%. The overall mean knowledge score of final year undergraduate health science students and interns was 11.1 (SD=0.2). The mean knowledge scores of nurses, interns, health officer, midwifery, anesthesia and psychiatry nursing students were 9.84 (SD=2.5), 13.34 (SD=2.8), 9.81 (SD=3.0), 8.77 (SD=2.6), 13.31 (SD=2.7) and 8.43 (SD=2.4) respectively. CONCLUSIONS: The knowledge level of undergraduate health professionals about cardiopulmonary resuscitation was insufficient. Training about CPR for undergraduate health professionals should be emphasized.