- Study Objective To evaluate whether socioeconomic status (SES) has a role in obstructive sleep apnea syndrome (OSAS) patients’ decision to accept continuous positive airway pressure (CPAP) treatment. Design Cross-sectional study; patients were recruited between March 2007 and December 2007. Setting University-affiliated sleep laboratory. Patients 162 consecutive newly diagnosed (polysomnographically) adult OSAS patients who required CPAP underwent attendant titration and a 2-week adaptation period. Results 40% (n = 65) of patients who required CPAP therapy accepted this treatment. Patients accepting CPAP were older, had higher apnea-hypopnea index (AHI) and higher income level, and were more likely to sleep in a separate room than patients declining CPAP treatment. More patients who accepted treatment also reported receiving positive information about CPAP treatment from family or friends. Multiple logistic regression (after adjusting for age, body mass index, Epworth Sleepiness Scale, and AHI) revealed that CPAP purchase is determined by: each increased income level category (OR, 95% CI) (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), family and/or friends with positive experience of CPAP (2.9, 1.1–7.5), and partner sleeps separately (4.3, 1.4–13.3). Conclusions In addition to the already known determinants of CPAP acceptance, patients with low SES are less receptive to CPAP treatment than groups with higher SES. CPAP support and patient education programs should be better tailored for low SES people in order to increase patient treatment initiation and adherence.