Restless legs syndrome (RLS), a neurological sensory-motor disorder characterized by a compelling urge to move the limbs during the night, is a sleep disturbance that impairs quality of life. Prevalence of RLS and consequences on quality of life were investigated in acromegalic patients. Fifty-six patients (20 men, 55.0 ± 1.6 years), 22 with active acromegaly (group 1) and 34 with controlled disease (group 2), and 95 controls (35 men, 52.9 ± 1.1 years) were evaluated by a structured sleep interview concerning insomnia, circadian sleep disorders and excessive diurnal sleepiness (EDS). The Epworth Sleepiness Scale (ESS) questionnaire was administered to those reporting EDS. Patients were investigated by RLS diagnostic interview and International Restless Leg Syndrome-Rating Scale (IRLS-RS). Quality of life was investigated by AcroQoL questionnaire. RLS was diagnosed in 21% of acromegalics and in 4% of controls (P < 0.002). Prevalence of RLS and mean IRLS-RS was higher in group 1 than in group 2 (P < 0.05). Prevalence of insomnia (P < 0.0002) and of EDS (P < 0.05) and mean ESS score (P < 0.01) were higher in RLS-positive than in RLS-free acromegalics. Video-PSG showed that mean sleep latency (P < 0.01), micro-arousal index (P < 0.05) and wakefulness after sleep onset (P < 0.01) were higher, whereas sleep efficiency (P < 0.01) was lower, in RLS-positive than in RLS-free patients. Global and physical AcroQoL scores were significantly lower in RLS-positive than in RLS-free acromegalics (P < 0.01 and P < 0.001, respectively). Prevalence and severity of RLS is increased in patients with active acromegaly and impacts negatively on their physical performances, dramatically impairing quality of life.