This research aims to determine the influence of website quality and electronic word of mouth on purchasing decisions through trust in the megabangunbangun.com website. The population used in this research were all consumers who made product purchase transactions provided on the megabangunbangun.com website during the research. The method used to take samples is a probability sampling method, which provides an equal chance for the population of each study to become the sample. The sampling technique uses simple random sampling carried out randomly according to known population characteristics. The number of participants in this study was 125. Model and data collection using questionnaires. The analysis method used is the SEM-PLS approach. The research results found that (1) website quality does not have a significant and positive effect on purchasing decisions, (2) electronic word of mouth does not have a significant and positive effect on purchasing decisions, (3) website quality has a significant and positive effect on trust, (4) electronic word of mouth has a significant and positive effect on trust, (5) trust has a significant and positive effect on purchasing decisions, (6) website quality has a significant and positive effect on purchasing decisions through trust, (7) electronic word of mouth has a significant and positive effect on decisions purchasing through trust, (8) website quality is the variable that has the most dominant influence in this research.