This study was performed to compare rectal midazolam and diazepam premedication on hemodynamics and sedation effects, separation from parents and intravenous cannulation scores in children undergoing urogenital surgery. Forty children, aged between 1 and 8 years, were divided into two groups. 0.5 mg $kg^{-1}$ midazolam + 0.02 mg $kg^{-1}$ atropine in the Midazolam Group (Group M), 0.5 mg $kg^{-1}$ diazepam + 0.02 mg $kg^{-1}$ atropine in the Diazepam Group (Group D) were administered rectally via an applicator 20 minutes before the onset of surgery. Systolic arterial pressure (SAP), heart rate (HR), arterial oxygen saturation (SpO2) were recorded before and after premedication and in the intraoperative and postoperative periods. The seperation and intravenous cannulation scores were noted. Sedation scores were evaluated before and after premedication and 20 minutes postoperatively. Postoperative pain was assessed by CHEOPS (Children's Hospital of Eastern Ontario Pain Scale). Nineteen patients in Group M, 10 patients in Group D were asleep and calm during parental separation (p<0.05). Intravenous cannulation scores were similar between the groups (p>0.05). Sedation scores were higher in Group M than Group D (p<0.05). The number of the patients with CHEOPS score of 5 and above in the first postoperative 15 minutes was lower in the Group M when compared to Group D (p<0.05). We found that rectal midazolam premedication was more effective than rectal diazepam for anxiety and parental seperation in children.