Canada is currently in the midst of an overdose crisis. With new and innovative approaches desperately needed, injectable opioid agonist treatment (iOAT) should be considered as an integral treatment option to prevent even more fatalities. These programs provide injectable diacetylmorphine or hydromorphone to clients with severe opioid use disorders. Currently, they remain an under‐executed and under‐studied treatment modality. To better understand why this may be, we performed an evolutionary concept analysis as described by Rodgers. The attributes, antecedents, consequences, and surrogate terms of iOAT were unpacked and explored. Further, four themes were identified within the literature: (1) physical and mental health, (2) illicit drug use, (3) criminal behavior, and (4) ethical considerations. Recommendations surrounding the need for additional studies that focus on the perspectives of people who use opioids (PWUO), the necessity of nursing advocacy in iOAT, and the consideration of a changing illicit drug supply were explored. Further, theoretical analysis coupled with direct input from PWUO was discussed as a necessity to move forward with iOAT.