Online product review and rating is considered one of the most important factors influencing the purchasing behaviour. Today ecommerce sites received massive number of reviews and it becomes difficult for customers to read all the reviews. Online product review is one of widely researched area and many researchers have proposed models to predict review helpfulness in ecommerce sites. This main objective of this research is to find the determinants of online review helpfulness. 12,389 online reviews related to 25 brands of mobile phones were collected from amazon.in. The results shows that word count is positively associated with helpfulness of the review. Star rating, neutral opinion and negative opinion are negatively associated with helpfulness of the review.