Effective utilization of business-to-business (B2B) electronic commerce (e-commerce) in hospitals may lead to many benefits such as increased accessibility to healthcare providers, improved process efficiency, enhanced quality of healthcare services, increased responses to changes, decreased scheduling conflicts, and reduction in administrative costs. However, many hospitals have found that they have not yet fully reaped the expected benefits from their B2B e-commerce investments. Despite this, there has not been much discussion in the literature with respect to the relationship between the organizational drivers on B2B e-commerce benefits for hospitals. Hence, a mixed-method of case study and survey was conducted to examine the relationships between B2B e-commerce benefits, IT evaluation resources allocation, IT investment evaluation methodologies, IT maturity, and user information requirements determination process. A B2B e-commerce evaluation management model was developed to test these relationships. The results provided empirical evidence in support of our proposed model and revealed that hospitals' IT evaluation resources allocation practices mediated the relationship of IT investment evaluation methodologies, IT maturity, and user information requirements determination process with B2B e-commerce benefits. The results also showed that the level of IT maturity had a significant impact on the adoption of IT investment evaluation methodologies.