Purpose: Research in engagement in social media has identified many highly effective applications. However, there is a lack of theoretical studies concerning consumer’s engagement in social media and trust of electronic Word of Mouth communication. Therefore, this study systematically reviewed the literature from the perspective of the Theory of Planned Behaviour. The purpose of this paper is to examine the engagement in social media and study multiple issues concerning communication and trust in online social communities, as well as the adoption of e-WOM as an influence parameter of consumer’s purchasing intentions. Design/methodology/approach: A descriptive cumulative review of the literature obtained articles published in relevant journals from 2018 to 2021 to examine the extent of trust in eWOM which occurred from the engagement of consumers in social media environment and identify patterns or trends with respect to pre-existing theories, methodologies or findings. Findings: The emerging results pointed out the Theory of Planned Behaviour as the cornerstone which explained the engagement in social media as well as the implications in
trusting e-WOM. Additionally, businesses shaped novel techniques to apprehend communication with their customers while at the same time they attempt to maximize their credibility. Although, new ways of e-WOM manipulation were developed. Consequently, maintaining increased levels of trustworthiness in consumers reviews is getting more and more mandatory as new exploits are discovered. Originality/value: A unified framework was created to locate concepts and to comprehend possible relationships. Most recent studies and developments concerning this subject are discussed.