Despite the growing interest and attention from IT researchers and practitioners, empirical research on the adoption of e-Marketplaces has been limited. This study identifies the factors influencing e-Marketplace adoption from an IT innovation perspective. Innovation, environment, and organization characteristics were tested as determinants of the adoption of an e-Marketplace based on a survey of 39 manufacturing firms. The findings indicate that external pressure and organizational size have positive relationships with organizational adoption of e-Marketplaces. Contrary to the prior innovation research, however, relative advantages did not have a significant impact on the organizational adoption of an e-Marketplace.