Open AccessIntramuscular injection of vaccines and medications into the deltoid muscle is a long-established nursing practice. The deltoid muscle is the preferred site for intramuscular injections to adult clients in community settings, as it requires minimal, generally socially-acceptable, exposure of the client’s body, and is easily accessible to the professional administering the injection. Nursing students learning to administer deltoid intramuscular injections raise excellent questions about deltoid intramuscular injection technique, in particular around landmarking technique, the use of bunching or flattening technique, and selection of needle length. Surprisingly little empirical evidence to guide the nurse, or to answer student questions about, administering deltoid intramuscular injections was found in the nursing and allied health literature. This article examines deltoid intramuscular injection practice with particular emphasis on teaching nursing students best practice.