Quality of Life (QoL) in patients with Obstructive Sleep Apnea Syndrome (OSAHS) is substantially reduced. OSAHS is as an important cause of morbidity and mortality as it is associated with a wide range of medical consequences (hypertension, cardiovascular diseases, psychological effects) and also accidents. Sleepiness, depression, fatigue and obesity have an important impact on QoL. Patients report problems in their social, professional and sexual relationships. Effective treatment of sleep apnea can improve the QoL of the patients and their families. As we live in an era of economic crisis cost effectiveness is crucial and in OSAHS the application of treatment with Continuous Positive Airway Pressure (CPAP) results in a significant reduction in healthcare costs, accidents and in an improvement of QoL of individuals and of society. This review focuses on the impact of OSAHS on quality of life and public health issues and the effectiveness of OSAHS treatment in these aspects.