The practice of medicine according to ethical principles requires that decisions regarding treatment, preventive or interventional strategies, or quality of life of patients in relation to life-support treatment should be based on evidence as far as possible. Available evidence for Hong Kong is reviewed under the following categories: use of drugs, management strategies, service provision, and interventions to prevent disease and/or disability. These examples highlight the need for studies to obtain evidence in the local population, as findings from studies in other countries may not be applicable. Although evidence exists in many areas to guide practice, the biggest challenge is how to implement such practice to ensure equitable access to prevention and treatment, particularly in the presence of health care resource limitations.