This study investigated the role of melatonin different doses as a premedication in decreasing the induction dose of propofol for anesthesia, preoperative anxiety, pain and sedation after abdominal surgery. This study was conducted on 60 patients scheduled for elective abdominal surgery under general anesthesia. The sixty patients included in this study were randomly divided into three equal groups(n=20)for each group: Control (C Group), melatonin 3mg (M3 Group) were received 3mg oral melatonin 100 min preoperative and melatonin 5mg (M5 Group) were received 5mg oral melatonin 100 min preoperative. The results revealed that mean induction dose of propofol was significantly higher in group C than in M3, M5 groups .Although the dose of propofol that result in loss of response to verbal commands and loss of eye lash reflex. VAS anxiety score preoperative and VAS pain score postoperative were statistically significant higher in C group than both melatonin groups. Time taken before the first dose of analgesia was significantly higher in both melatonin group than the control group.