This article follows current research on English for Specific Business Purposes, which focuses on the analysis of contextualized business genres and on identifying the strategies that can be associated with effective business communication (Nickerson, 2005). It explores whether free internet dictionaries can be used for promoting effective business communication by presenting a detailed analysis of the definitions and encyclopedic information associated with three business terms that are retrieved from "YourDictionary.com", and "BusinessDictionary.com". Our results indicate that these two dictionary structures can be very effective for acquiring business knowledge in cognitive use situations. Hence, this paper makes a case for presenting free internet dictionaries as adequate tools for guiding instructors and learners of Business English into the new avenues of knowledge that are already forming, which are characterized by an interest in continuous retraining, especially in the field of ESP where both teachers and students have to deal with areas of knowledge with which they might not be very familiar. (Contains 2 tables.)