A retrospective study investigated the association of serum creatinine to albumin ratio (CAR) with 1-year mortality in elderly patients after in-hospital hip fracture surgery from January 2018 to December 2023. The mean age of patients was 79.5 ± 8.1 years and the median CAR was 1.9 (1.5–2.4). The prevalence of 1-year mortality after surgery was 8.6%. Multivariate Cox regression analysis showed that high CAR was independently associated with increased 1-year mortality (hazard ratio 1.49; 95% confidence interval 1.02–2.17) after adjustment for covariates. Kaplan-Meier curves confirmed higher 1-year mortality in patients with high CAR versus low CAR (p < 0.0001). Subgroup analyzes showed a similar association in all groups. CAR may serve as an independent indicator of 1-year mortality in these patients, but the findings need to be confirmed by further studies.