OBJECTIVES: To evaluate whether socioeconomic status (SES) plays a role in the patient's decision to accept (purchase) continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea syndrome (OSAS) (according to the Israeli National Health Insurance Law, purchasing CPAP treatment requires an out-of-pocket payment). METHODS: Cross-sectional prospective study in the University-affiliated Sleep Disorder Center in Beer-Sheva, Israel. Adult patients (age>18 years), suspected of having OSAS, were consecutively recruited between March 2007 and December 2007. Questionnaires were completed prior to diagnosis to elicit socioeconomic status, sleeping habits, and access to sources of information on OSAS and its treatments. At the conclusion of the adaptation period, a second questionnaire was completed to explore the reasons for commencing or declining treatment. RESULTS: Among the newly diagnosed (polysomnographically) adult OSAS patients, 162 required CPAP and underwent attendant titration and a 2-week adaptation period. Only 40% of these patients (n = 65) decided to purchase CPAP therapy. They were older, and typically they had higher apneahypopnea indexes (AHIs) and higher income levels than the patients who declined CPAP treatment. Multivariate logistic regression (adjusting for body mass index and Epworth Sleepiness Scale) revealed that whether a patient purchased CPAP was determined by (OR, 95% CI): income level (2.4; 1.2-4.6), age (+1 year) (1.07; 1.01-1.1), AHI ( ≥ 35 vs. < 35 events/hr) (4.2, 1.4-12.0), receiving positive feedback about the experiences of family or friends with CPAP (2.9, 1.1-7.5), and sleeping separate from spouse (4.3, 1.4-13.3). CONCLUSIONS: In addition to the already known determinants of CPAP acceptance, patients with low SES were less receptive to CPAP treatment than those with higher SES. CPAP support and patient education programs should be tailored for low SES people in order to increase rates of treatment initiation and adherence.