While research indicates that both the macro- and microstructure of sleep may be altered in fibromyalgia syndrome, few studies have controlled for symptom duration or included pain-control participants (i.e. patients with chronic pain and sleep disturbance not associated with fibromyalgia syndrome). A frequently reported alteration found in the sleep microstructure of patients with fibromyalgia syndrome is the alpha-delta sleep anomaly. Although alpha waves have been observed during N3 sleep in healthy individuals, it has been proposed that there is an increase in alpha wave activity during slow-wave sleep in fibromyalgia syndrome. Originally considered a possible neurological contribution to fibromyalgia syndrome, whether the alpha-delta sleep anomaly is fundamental to the development of fibromyalgia syndrome, or results mainly from the pain experience remains unknown. The present study was designed to compare sleep macro- and microstructure, and psychometric profiles, in three broadly age-matched groups of female participants: patients with fibromyalgia syndrome (n = 19); patients with osteoarthritis with sleep disturbance (n = 17); and healthy adults (n = 10). Patients with fibromyalgia syndrome met the American College of Rheumatology diagnostic criteria and were recruited within 6 months of diagnosis. Subjective sleep quality was significantly lowest, and levels of anxiety and depressive symptoms were significantly highest for patients with fibromyalgia syndrome. However, the groups showed no significant differences in polysomnographic measures of total sleep time, sleep latency and total wake after sleep onset. Levels of alpha-delta sleep were statistically similar in both clinical (fibromyalgia syndrome and osteoarthritis) groups, indicating that it is not a specific abnormality of fibromyalgia syndrome. Overall, subjective measurements of anxiety, depression, fatigue and sleep quality better discriminated between the three groups than did objective measurements of sleep variables.