In e-marketplaces with limited inventory where buyers’ demand is larger than sellers’ supply, promoting honesty raises new challenges: sellers may behave dishonestly because they can sell out all products without the necessity of gaining high reputation; buyers may provide untruthful ratings to mislead other buyers in order to have a higher chance to obtain the limited products. In this paper, we propose a novel incentive mechanism to promote buyer and seller honesty in such e-marketplaces. More specifically, our mechanism models both buyer and seller honesty. It offers higher prices to the products provided by honest sellers so that the sellers can gain larger utility. Honest buyers also have a higher chance to do business with honest sellers and are able to gain larger utility. Experimental results confirm that our mechanism promotes both buyer and seller honesty.