OBJECTIVE The aim of this randomized, double-blinded, prospective study was to determine the effectiveness and side effects of intravenous or epidural use of morphine, bupivacaine or ropivacaine on post-thoracotomy pain management. METHODS Sixty patients undergoing elective thoracotomy procedure were randomly allocated into 4 groups by the sealed envelope technique. Group IVM, EM, EMB and EMR received patient controlled intravenous morphine, and epidural morphine, morphine-bupivacaine and morphine-ropivacaine, respectively. Perioperative heart rate, blood pressure and oxygen saturation and postoperative pain at rest and during cough, side effects and rescue analgesic requirements were recorded at the 30(th) and 60(th) minutes and the 2(nd), 4(th), 6(th), 12(th), 24(th), 36(th), 48(th), and 72(nd) hour. RESULTS Diclofenac sodium requirement during the study was lower in Group EM. Area under VAS-time curve was lower in Group EM compared to Group IVM, but similar to Group EMB and EMR. Pain scores at rest were higher at the 12, 24, 36, and 48(th) hour in Group IVM compared to Group EM. Pain scores at rest were higher at the 30(th) and 60(th) minutes in Group EM and Group IVM compared to Group EMB. Pain scores during cough at the 30(th) minute were higher in Group EM compared to Group EMB. There was no difference between Group IVM and Group EMR. CONCLUSIONS Morphine used at the epidural route was found more effective than the intravenous route. While Group EM was more effective in the late period of postoperative, Group EMB was more effective in the early period. We concluded that epidural morphine was the most effective and preferred one.