Abstract: Objective To analyze the association of preoperative C-reactive protein (CRP) level with postoperative complications in elderly patients undergoing surgeries for femoral neck fracture. Methods We retrospectively analyzed the data of 147 elderly patients (median age 80 years; 73.5% of the patients were female) undergoing surgeries for femoral neck fracture. According to preoperative CRP level, the patients were divided into normal CRP (<10 mg/L) group (31 patients), mild elevation group (CRP level of 10-40 mg/L; 51 patients), and severe elevation group (CRP ≥40 mg/L; 65 patients). The association of preoperative CRP levels with postoperative complications was analyzed. Results Preoperative CRP level was significantly correlated with the occurrence of postoperative complications (P=0.003). Compared with that in normal CRP group, the unadjusted ORs in mild and severe elevation groups were 0.97 (95%CI: 0.29-3.27) and 3.04 (95%CI: 1.03-8.98) with the adjusted ORs of 1.13 (95%CI: 0.33-3.90) and 4.89 (95%CI: 1.47-16.26), respectively. Conclusion Preoperative CRP level has a dose-response relationship with complications in elderly patients following arthroplasty for femoral neck fracture, and the patients with a preoperative CRP level ≥40 mg/L are exposed to a significantly increased risk for postoperative complications by 3.89 folds compared with the patients with a normal CRP level.