With the development of Internet and e-commerce, traditional word of mouth communications have evolved into electronic word of mouth (eWOM) communications, which significantly affect consumers in their decision-making process. Previous studies investigated how consumers process information online and how it affects consumer behaviour applying the Elaboration Likelihood Model (ELM). ELM distinguishes between two routes of information processing: central and peripheral. Existing literature has a mixed of findings regarding factors affecting information process using ELM and lacking a comprehensive review providing evaluation and a consolidated view of these factors. Thus, the aim of this research is to evaluate the use of ELM in the context of eWOM research by performing a systematic review and weight analysis of existing research findings. This will help consolidating the predictive power of the independent variables on the dependent variable, by taking into consideration the number of times a relationship has been previously examined. The model developed through weight analysis would allow eWOM practitioners to decipher more influential factors.