An ongoing debate addresses the usefulness of asynchronous versus synchronous e-learning. "Asynchronous e-learning," commonly facilitated by media such as e-mail and discussion boards, supports work relations among learners and with teachers, even when participants cannot be online at the same time. "Synchronous e-learning," commonly supported by media such as videoconferencing and chat, has the potential to support e-learners in the development of learning communities. In this article, the author presents a research study that focuses on the benefits and limitations of asynchronous and synchronous e-learning and addresses questions such as when, why, and how to use these two modes of delivery. (Contains 3 tables, 1 figure, and 22 endnotes.)