Objective To analyze the predictive value of the Charlson comorbidity index (CCI) for postoperative complications of femoral intertrochanteric fractures in the elderly. Methods A retrospective cohort study was conducted on 378 elderly patients who underwent hip surgery for femoral intertrochanteric fractures between January 2017 and January 2018 in our hospital. Taking CCI=4 points as standard, they were divided into high-risk group (CCI ≥4 points) and a low-risk group (CCI＜4 points). The primary study endpoint was occurrence of complications within 30 d postoperatively. SPSS statistics 22.0 was used for statistical analysis. Student′s t test or Chi-square test was performed for comparison between two groups depending on data type. Cox regression analysis was adopted to determine the relationship between CCI and postoperative complications. Results Of the 378 patients, there were 67 patients in the high-risk group and 311 in the low-risk group. The high-risk group had significantly higher incidence of postoperative complications [64.2% (43/67) vs 49.8% (155/311)], ratio of postoperative admission to ICU [29.9% (20/67) vs 16.7% (52/311)], and proportion of general anaesthesia [50.7% (34/67) vs 37.6% (117/311)] than the low-risk group (all P<0.05). In the multivariate model, CCI was significantly associated with postoperative complications (RR=1.13,95%CI 1.011-1.253, P=0.026). Other risk factors included general anesthesia (RR=1.59,95%CI 1.373-1.943, P=0.026) and postoperative ICU stay (RR=1.34,95%CI 1.180-1.642, P=0.001). Conclusion CCI can be used to assess and predict postoperative complications in elderly patients with intertrochanteric femoral fractures.