E-marketplaces present a business-to-business (B2B) trading environment in which firms can benefit from increased choice among trading partners, and other efficiencies gained through electronic trading. B2B e-marketplaces have only recently emerged in New Zealand; however, there is already doubt whether predicted benefits are being realized. This study draws on the Tornatzky and Fleischer (1990) adoption model to explore the motivations and barriers to e-marketplace adoption that agricultural micro-enterprises experience. Key perceived barriers of e-marketplace adoption include conflict with pre-existing relationships, risk perceptions, ease of use and infrastructure problems. Dominant motivations include the ability to exclude the agent middleman, a reduction in transaction costs, and market reach. E-marketplace owners can use these preliminary findings to reduce perceived barriers and encourage increased participation. They also extend our understanding and assist theory development of the factors influencing micro enterprise adoption and participation in e-marketplaces, and within the agricultural sector.