Fibromyalgia syndrome [FM] has core clinical features of widespread pain and widespread abnormal tenderness. The specific cause of the altered neurophysiology that underpins these clinical manifestations remains unclear. However, increased sensitisation of neural networks that relates to pain, as well as interacting mechanoreceptors, appear important targets for modulation by pharmacological agents. Further, many FM patients have emotional distress and some are depressed. Antidepressant agents have therapeutic benefits in FM. If depression is present antidepressant drugs will provide typical benefits to mood but not always to other key outcome measures, such as pain or tenderness. Selective serotonin receptor reuptake blockers are not as effective for overall FM improvement as drugs that block both serotonin and norepinephrine in a relatively balanced way. Thus tricyclic antidepressants will improve many important FM outcomes but are effective in only about 40 percent of individuals. Newer agents of this class, such as duloxetine and milnacipran, show improvement in key FM outcomes in about 60 percent of patients. Longer term studies will indicate the durability of these responses and the overall tolerance of the drugs. Any drug therapy will need to be integrated with appropriate education, exercise and attention to psychological modulatory factors to achieve best results.