Effective treatment of perioperative acute pain requires that information about the patient's goals for pain relief, previous history with analgesics, and type of surgical procedure is used to guide decisions about analgesic regimens. Analgesics are selected based on the location of surgery, degree of anticipated pain, and patient characteristics such as comorbidities, and routes of administration and dosing schedules are determined to maximize the effectiveness and safety of analgesia, while minimizing the potential for adverse events. Pain management therapy is then extended into the postsurgical phase of recovery. To accomplish this, nurses must have a thorough understanding of the pharmacology of analgesics. This article provides useful information for commonly used analgesics, primarily nonsteroidal antiinflammatory drugs (NSAIDs), opioids, and local anesthetics for control of acute postoperative pain.