Amaç: Son zamanlarda, preoperatif sistemik enflamatuar yanıtın kolorektal kanserli hastalarda (CRC) prognostik bir faktör olduğu bildirilmiştir. Bu bağlamda preoperatif nötrofil lenfosit oranı (NLO), prognoz için faydalı bir öngörü faktörü olarak öne sürülmüştür. Bu çalışmada nötrofil/ lenfosit oranının kolorektal kanser nedeniyle cerrahi tedavi uygulanan hastalarda postoperatif komplikasyonları öngörebilmedeki klinik değerini ve prognostik önemini saptamayı amaçladık. Yöntem: 2015-2019 yılları arasında kolorektal kanser nedeniyle cerrahi tedavi, uygulanan hastalar çalışmaya dahil edili. Grup 1 (NLO düşük) ve grup 2 (NLO yüksek) olmak üzere iki grup oluşturuldu. Gruplarda hastaların demografik ve klinik özellikleri intraoperatif ve postoperatif sonuçlarları ortalama sağkalımları karşılaştırıldı. NLO belirlenen cut off değerinde postoperatif komplikasyonları öngörebilmedeki değerine bakıldı. Bulgular: Hastalar 2,08 cutoff değerine göre iki gruba ayrıldı grup 1=56 hastadan grup 2=223 hastadan oluşuyordu Her iki grupta da erkek cinsiyet baskındı (%60 vs,%64 p=0,349), grup 2'deki hastalar daha çok neoadjuvant tedavi almıştı (%29,1 vs %12,5 p=0,007), intraoperatif komplikasyon ÖZ Aim: Recently, the preoperative systemic inflammatory response has been reported to be a prognostic factor in patients with colorectal cancer (CRC). In this context, the preoperative neutrophil/lymphocyte ratio (NLR) has been proposed as a useful predictor of prognosis. In this study, we aimed to determine the clinical value and prognostic significance of neutrophil/lymphocyte ratio in predicting postoperative complications in patients undergoing surgical treatment for colorectal cancer. Method: Patients who underwent surgical treatment for colorectal cancer between 2015-2019 were included in the study. group 1 (Low NLR) and group 2 (High NLR) were formed. Demographic and clinical characteristics, intraoperative and postoperative results, and mean survival were compared. The value of NLR in predicting postoperative complications at the determined cutoff value was examined. Results: Patients were divided into two groups according to the cutoff value of 2.08. Group 1 consisted of 56 patients, and group 2 consisted of 223 patients. Male sex was dominant in both groups (60% vs 64%, p=0.349), while patients in group 2 received more neoadjuvant treatment (29.1% vs 12.5%, p=0.007). Intraoperative complication rates were similar (1.8% vs 4%, p=0.369), pathological grade (p=0.031), and stage (p=0.113) were similar. Postoperative complications were more common in group 2 (24.7% vs 10.7%, p=0.015). Total survival was shorter in group 2 (46 months vs. 52 months, p=0.025). At the determined cutoff value, NLR predicted postoperative complications with 22.94% specificity and 90.6% sensitivity. Conclusion: High NLR was associated with postoperative complications and survival. Although it has a prognostic value, its value in predicting postoperative complications is limited and cannot be used alone.