Background. Previously, effects of preoperative sedatives were assessed mainly with respect to preoperative outcomes such as anxiety and compliance. The purpose of this investigation was to evaluate the effects of preoperative sedatives on postoperative psychological and clinical recovery. Methods: Patients undergoing general anesthesia and outpatient surgery were enrolled in a double-blind, randomized, placebo-controlled trial. Subjects (n = 55) were randomly assigned to receive either 5 mg intramuscular midazolam (n = 26) or a placebo injection (n = 29) at least 30 min before surgery. The anesthetic technique was controlled. Postoperative anxiety, pain, analgesic consumption, clinical recovery parameters, and global health (SF-36) were evaluated up to 1 month after surgery. Results: Surgery length did not differ significantly between the treatment and placebo groups (118 ± 45 min vs 129 ± 53 min; P = NS). Throughout the first postoperative week, subjects in the treatment group reported a greater reduction in postoperative pain compared with subjects in the placebo group (F(1,50) = 3.5; P = 0.035). Moreover, at 1 week, ibuprofen use was reported by less subjects in the treatment group than in the placebo group (0% vs 17.2%; P = 0.026). Subjects in the treatment group also reported a greater reduction in postoperative anxiety throughout the follow-up period (F(1,53) = 9.2; P = 0.04). However, global health indexes (SF-36) did not detect any significant differences between the two experimental groups (multivariate F(1,45) = 0.44; P = 0.51). Conclusion: Subjects treated with midazolam preoperatively self-report improved postoperative psychological and pain recovery. However, the clinical significance of these findings is unclear at the present time.