Chronic lymphocytic leukaemia is one of the most common types of adult leukaemia. Cancer-related systemic inflammation response has been characterized to correlate with therapeutic outcome in patients with cancer. The C-reactive protein-to-albumin (CRP/ALB) ratio (CAR), which is an inflammatory marker, has been reported as a novel prognostic factor in several cancers. The aim of our study was to evaluate the prognostic value of the CAR in patients with chronic lymphocytic leukaemia (CLL). We retrospectively reviewed the clinical characteristics of 322 newly diagnosed CLL patients, investigated the correlations among pretreatment CAR, treatment-free survival (TFS) and overall survival (OS), assessed the prognostic effect of the CAR to compare with other inflammation-related prognostic index by the area under the curve (AUC), and combined CAR and CLL-international prognostic index (CLL-IPI) together to improve the current prognostic system. The results showed that CAR was an independent prognostic factor for OS. Furthermore, the predictive and discriminatory capacity of CLL-IPI together with CAR level was superior to that of CLL-IPI alone for OS. In conclusion, serum CRP and ALB levels are both simple and easily accessible parameters, whose ratio CAR may be good candidates for predicting prognosis in the future clinical practice of CLL.