Fibromyalgia is a significant clinical problem associated with generalized pain and significant interference with daily activities. Although a variety of treatment modalities have been utilized, clinicians have struggled to find an effective means of treatment. Therefore, this study assessed the efficacy of the atypical neuroleptic olanzapine for the treatment of fibromyalgia symptoms. To examine the efficacy of olanzapine for the treatment of fibromyalgia symptoms, the charts of 51 patients treated with olanzapine were evaluated for improvements in pain and daily life functioning. At the time of initial assessment, patients had been diagnosed with a variety of medical and psychiatric disorders and a history of neuroleptic treatment. Pain was widespread and characteristic of pain associated with fibromyalgia. Pretreatment ratings on pain and the interference scales averaged 6.54-8.69 on a 0-10 scale. Post-treatment ratings on the same scales revealed significant improvement on virtually all scales. The benefits of olanzapine to improve fibromyalgia symptoms must, however, be carefully considered because there were a variety of side effects (i.e., weight gain, somnolence/sedation) that were of sufficient strength to cause a number of patients to discontinue treatment. In general, the data provide strong support that olanzapine can, in certain patients, improve symptoms associated with fibromyalgia in patients who have had limited success with other treatment modalities.