Opioid rotation is a strategy applied during opioid therapy for pain that refers to a switch from one opioid to another in an effort to improve clinical outcomes (benefits or harms). It begins with the selection of a new drug at a starting dose that minimizes potential risks while ideally maintaining analgesic efficacy. The selection of a starting dose must be informed by an estimate of the relative potency between the existing opioid and the new one. Clinically relevant estimates of relative analgesic potency have been codified in the "equianalgesic dose table," which has been used with little modification for more than 40 years. New information about relative potency and the growing implementation of long-term opioid therapy for chronic pain provided a strong rationale for the convening of an expert panel to discuss the scientific foundation to opioid rotation and the elements that now should inform a clinical guideline for this practice. The panel affirmed both the value and the limitations of the current equianalgesic dose table and proposed a guideline intended to promote safety during opioid rotation.