Administering injections is an activity inherent to nursing practice. A critical review of nursing fundamentals texts found that the "proper" procedure was often non-research based and reflected myths, traditions, and out-of-date recommendations regarding the technique. This article is an integrative review of the extensive research conducted by a variety of researchers in health-related disciplines during the last seven decades. The pertinent research is reviewed and critiqued and serves as the basis for a clinical practice protocol. This research-based procedure ensures efficient and effective nursing care related to intramuscular injections.