Purpose: To investigate the effects of online reviews on consumer purchase intention considering the moderating role of product involvement and consumer expertise. Methodology: To reach our goal in this paper, we conduct a descriptive study in a deductive way. This is quantitative research in which the relationship between online reviews and consumer buying behavior will be tested. The research strategy of the study is an online survey. The sample size is 200 respondents considering confidence level 95% and confidence interval 7. Data editor IBM SPSS is used to performing the data analysis. Findings: High-low product involvement and high-low consumer expertise have an impact on the factor of online review (quality, quantity, and credibility) significantly and it affects the purchase intention of the consumer. The study created a conceptual model, which is adapted from the ELM model that considers expertise, involvement, perceived quality, quantity credibility of online consumer review and intent to purchase. This study found that the effect of review type (quality) on the intention of purchase was stronger for both experts and novice and both high-low involvement products. Depending on the level of involvement, the quantity of review on purchase intention increases but the quantity of review on the intention to purchase did not differ under both low involvement & high expertise. Again, individuals rely on source credibility when product involvement is low. But the credibility of the review did not differ on the purchase of intention under low involvement and low expertise situation. Research implications: This study applies the ELM model to measure the cognitive factor (review factor) and motivation factor (involvement and expertise) together. This study shows consumers with different levels of involvement and expertise prefer different levels of online review factors. The marketer could classify online review information into different category lines like the attribute-based review, benefit-based review, etc. and based on the analysis, the marketer can make a different plan for a different level of consumer (expert and involved consumer). Keywords: Quality, quantity, and credibility of review, Product involvement, consumer expertise, elaboration likelihood model (ELM Model).