Background:Surgical site infections (SSIs) are infections that develop within 30 days after an operation or surveillance of surgical wound infection implementation within 90 days after surgery when an implant is placed. The objective of this study was to assess preoperative and postoperative antimicrobial use in St. Paul’s Hospital Millennium Medical College (SPHMMC), Addis Ababa, Ethiopia.Methods:A hospital-based cross-sectional study was undertaken in surgery wards of SPHMMC for 4 months by reviewing 413 patients’ charts. All patients 13 years and older who were admitted and underwent different types of surgical procedures were included in the study. Epi info 7 was used for data entry, and then data were exported to Statistical Package for Social Sciences (SPSS) version 20.0 software for analysis. Descriptive analyses were computed and rate of SSI was calculated in this study. Moreover, bivariate analysis was done to examine the relationship between the outcome variable and predictor variables with a value of P < .2 retained for subsequent multivariate analyses using multiple logistic regressions. P value of <.05 was considered as statistically significant.Results:Out of 413 patients, 152 (36.8%) were operated for general surgery, and the remaining were for other types of surgeries. Most of the patients, 196 (79.7%), were managed by a single surgical antibiotic agent, followed by 2 agents (20.3%) for surgical prophylaxis indication. Surgical site infections occurred in 46 (11.1%) patients before discharge from the hospital. In those patients who need treatment for SSIs, almost half of them (49.5%) received combination therapy of ceftriaxone and metronidazole. Emergency surgical cases were 2.647 times more likely to develop SSIs than the elective surgical cases (adjusted odds ratio [AOR] = 2.647; 95% confidence interval [CI] = 1.406-4.983; P = .003). Patients who did not receive antibiotic prophylaxis were 2.572 times more likely to develop SSIs compared to those who received antibiotic prophylaxis (AOR = 2.572; 95% CI = 1.02-6.485; P = .045). Clean-contaminated and contaminated types of wound were a protective factor against SSI in our study.Conclusions:This study indicated that most of the patients (72.1%) received surgical antimicrobial prophylaxis. The overall incidence rate of SSIs was 11.1% in the studied hospital. Ceftriaxone was the most commonly used drug. Being not receiving prophylaxis, wound class, and surgery types were significantly associated with the development of SSI.