Most internet users in Malaysia still have doubts about pursuing online purchases, primarily due to their attitude and perception toward online transactions. Addressing this issue, this study aims to examine how consumer attitude mediates the relationship between consumerto-consumer communication and online purchase intentions. This study contributed to a new factor in consumer-to-consumer communication, namely product knowledge. Besides product knowledge, other factors such as argument quality, source of credibility, and tie strength were examined. Approximately 200 Malaysian internet users voluntarily participated in this study. The quantitative data analysis was conducted with a descriptive analysis using the Statistical Package for Social Science (SPSS) version 21.0. The path analysis, specifically Partial Least Squares Structural Equation Modeling (PLS-SEM), was performed using SmartPLS version 2.0. The findings revealed consumers' online purchase intention was positively affected by consumer-to-consumer (C2C) communication factors, particularly argument quality and source of credibility.