Introduction: Joint Commission predicted that 80 % of the serious safety events occur due to miscommunications among healthcare professionals. Speaking up is one of the critical behaviors of patient safety that displays an important role for improving quality and patient safety in healthcare. Objectives of this study are 'assessing the effectiveness of speaking up for patient safety', 'identifying the influencing factors of speaking up', 'evaluating the effectiveness of speaking up training' and 'finding enablers of speaking up'.Methods: This study was done to identify literature about 'speaking up' behaviors to improve safety outcomes via considering both patient and provider perspectives. Varied databases were used to find English articles that relevant to both patient and provider's speaking up behaviors that mainly focused to demonstrate its impact on patient safety outcomes. Data was extracted and analyzed to find influencing factors and recommended voicing up behaviors that display important role for improvement in quality and safety of healthcare. Results: 53 relevant articles were identified in 83 articles. Those 53 articles consist of 4 literature reviews, 3 RCTs, 8 cohorts, 1 case control, 34 cross sectional studies and 3 reports. This study is the first study about not just identifying factors that influencing speaking up behaviors among providers but also including factors of patients' voicing up behaviors for safety. This study is also providing some 'enablers of speaking up behaviors' which may help healthcare leaders and professionals' decision making process for quality and safety improvements in their organization. Conclusions: Speaking up is one of the critical behaviors of patient safety. Awareness of factors that 'influencing' and 'enabling' speaking up behaviors may help leaders and decision makers to improve quality and safety of healthcare in their organization. This study is providing complex process of speaking up behavior and their impacts on patient safety outcomes.