Introduction <p>Perineal wound infection following abdominoperineal resection for rectal cancer is a common postoperative complication. Identifying factors associated with perineal wound infection can help reduce morbidity. This study aimed to identify risk factors for perineal wound infection following abdominoperineal resection for rectal cancer.</p> Methods <p>This was a retrospective cross-sectional study involving 70 patients with rectal cancer who underwent abdominoperineal resection at Viet Duc University Hospital between January 1, 2015, and December 31, 2022. Patients were categorized into two groups based on the presence or absence of perineal wound infection. Potential risk factors were compared between the two groups, including: age, BMI, presence of diabetes mellitus, preoperative chemoradiotherapy, preoperative laboratory indices (hemoglobin, albumin, white blood cell count), tumor diameter, tumor stage, and operative time.</p> Results <p>Perineal wound infection occurred in 38 out of 70 patients (54.3%). Univariate analysis revealed that undernutrition, indicated by BMI &lt; 18.5&#xa0;kg/m² (<i>p</i> = 0.047), and preoperative hypoalbuminemia (albumin &lt; 35&#xa0;g/L) (<i>p</i> = 0.004), were significantly associated with an increased risk of perineal wound infection. Multivariate analysis identified diabetes mellitus (<i>p</i> = 0.02) and preoperative hypoalbuminemia (<i>p</i> = 0.02) as independent risk factors for perineal wound infection following abdominoperineal resection for rectal cancer.</p> Conclusion <p>Univariate analysis indicated that malnutrition (BMI &lt; 18.5&#xa0;kg/m²) and preoperative hypoalbuminemia (albumin &lt; 35&#xa0;g/L) were significantly associated with perineal wound infection. Multivariate analysis identified diabetes mellitus and preoperative hypoalbuminemia as independent risk factors that increased the likelihood of perineal wound infection following abdominoperineal resection for rectal cancer.</p>