This is the tenth in a series of articles about the science of quality improvement. We explore how evidence-based healthcare relates to quality improvement, implementation science and the translation of evidence to improve healthcare practice and patient outcomes. Evidence-based practice integrates the individual practitioner's experience, patient preferences and the best available research information. Incorporating the best available research evidence in decision making involves five steps: asking answerable questions, accessing the best information, appraising the information for validity and relevance, applying the information to care of patients and populations, and evaluating the impact for evidence of change and expected outcomes. Major barriers to implementing evidence-based practice include the impression among practitioners that their professional freedom is being constrained, lack of appropriate training and resource constraints. Incentives including financial incentives, guidance and regulation are increasingly being used to encourage evidence-based practice.