Abstract Background An appropriately administered surgical antimicrobial prophylaxis decreases the rate of surgical site infections. Although evidence-based clinical practice guidelines have been published on surgical antimicrobial prophylaxis, the rate of adherence to the protocol and the impact of extending antimicrobial prophylaxis postoperatively is yet to be well elucidated. Method A total of general surgery and vascular surgery patients with clean and clean contaminated wound undergoing elective surgical procedures were included in the study. The rate of surgical antimicrobial prophylaxis utilization, the proportion of patients whom had their antimicrobial prophylaxis extended beyond 24 h and the rate of surgical site infections across groups were evaluated. Results The surgical antimicrobial prophylaxis utilization rate was 90.5%. Of these patients, 12.6% were unnecessarily administered with antibiotics. An “extended” antibiotics administration beyond 24 h after the surgery was found in 40.2%. Gastrointestinal and hepato-pancreatico-biliary surgery patients had 7.9-fold rate of “extended” surgical antimicrobial prophylaxis beyond 24 h, AOR 7.89 (95% CI 3.88–20.715.62, p value < 0.0001). The overall rate of surgical site infection was 15(6.8%). The “extended” regimen of prophylactic antibiotics had no effect on the rate of surgical site infections. Conclusion Less than half of the patients included here had surgical antimicrobial prophylaxis regimen in accordance with the existing guidelines. The most common protocol violation was noted as extension of antimicrobial prophylaxis for more than 24 h after surgery. The extension of antimicrobial prophylaxis did not decrease the rate of surgical site infections, reaffirming the evidence that prophylactic extension of surgical antimicrobial prophylaxis is unnecessary.