Utilization of Chinese Medicine (CM) is not uncommon in patients with chronic lymphocytic leukemia (CLL). However, the current knowledge of the usage and efficacy of CM among CLL patients is limited. The aim of this study was to determine the impact of integrative Chinese Herbal Medicine (CHM) on the disease course of CLL and ascertain the herbal products most commonly prescribed to patients with CLL.A Taiwanese nationwide population-based study involving the use of Western medicine and CM services provided by the National Health Insurance (NHI) was conducted.An NHI Research Database-based cohort study was performed; the timeframe of the study was January 2000 to December 2010. The end of the follow-up period was defined as December 31, 2011.A total of 808 patients were diagnosed with CLL in Taiwan within the defined study period. After randomly matching for age and sex and excluding patients younger than 18 years of age, data from 616 patients were analyzed.The 2 study groups both received standard of care treatment. In addition, 1 group also received CHM. Patients who were registered as receiving other forms of CM, such as acupuncture, were excluded.Hazard ratios of mortality were used to determine the influence of CHM and the therapeutic potential of herbal products.In total, 616 CLL patients were included in the analyses. We found that the HR associated with the adjunctive use of CHM was less than half when compared to the non-CHM group (0.43, 95% CI 0.33-0.55, P < 0.0001) and that treatment-naive patients who used CHM had the lowest HR. We also established that this association between reduction in HR and CHM was dose-dependent, and the longer CHM users received prescriptions, the lower the HR (P < 0.001).We supplied data from a relatively large population that spanned a significant amount of time. Our data suggests that the treatment of CLL with adjunctive CHM may have a substantial positive impact on mortality, especially for treatment-naive patients. Further research is needed to confirm whether there is a direct causal relationship between CHM and the outcomes displayed.