Background: Post discectomy discitis is regarded as the most disabling cause of failed back surgery. Value of local intra-operative application of antibiotics in prevention of such complication has been a matter of debate. We evaluate the role of intraoperative intra-discal vancomycin powder instillation as a prophylaxis in prevention of postoperative discitis in patients undergoing microscopic discectomy. We allocated 100 patients undergoing discectomy equally into two groups. In the frst group, a local Vancomycin powder was inserted into the disc space after fnishing discectomy, and in the second group, nothing was inserted. Results: The postoperative discitis was reported in 6 cases; of them, two patients were in the Vancomycin group (4%), while four patients were in the non-Vancomycin group (8%). Conclusions: We concluded that the intra-operative prophylaxis, with intra-discal Vancomycin, decreased the incidence of postoperative discitis but without signifcant statistical diference. We advocate using local vancomycin especially in high risk patients for prevention of post discectomy discitis. Keywords: Lumber discectomy, Discitis, Vancomycin, Prevention