CONTEXT: Obstructive sleep apnea syndrome (OSAS) emphasize the concurrence and interaction of disorders of lipid metabolism and components of metabolic syndrome (MS) such as insulin resistance.AIMS: The aim of this study is to observe the effect of positive airway pressure (PAP) treatment on the lipid profile during 1‑year follow‑up of patients diagnosed with OSAS.SETTINGS AND DESIGN: This was a single‑center, retrospective, observational study.MATERIALS AND METHODS: A total of 168 OSAS patients were diagnosed in our sleep laboratory and were recommended for PAP therapy. Among these patients, 64 patients who received effective PAP treatment for 1 year, and who did not have the comorbid disease, history of lipid‑lowering treatment, or history of lifestyle change, dietary regulation or attempt to loose weight during the 1‑year follow‑up period were included in the study. Pretreatment measurement parameters including body weight, waist, neck and hip circumference, body mass index (BMI), blood lipid levels (total cholesterol [TC], triglyceride [TG], high‑density lipoprotein [HDL], low‑density lipoprotein [LDL]), and Epworth sleepiness scale (ESS) score were compared with the 3rd and 12th months parameters.STATISTICAL ANALYSIS USED: SPSS version 16 (SPSS Inc., Chicago, IL, USA) was used for the statistical analyses.RESULTS: The study included 64 (38 M, 26 F) patients (mean age of 53.1 years). The mean apnea‑hypopnea index was 50.84 h. Although TC, HDL, LDL, and TG levels did improve with the PAP treatment (all P < 0.05), no significant decrease was observed with respect to the BMI, hip, neck, and waist circumference (all P > 0.05). There were statistically significant changes in sleep efficiency, oxygen desaturation index, and ESS score (P < 0.05).CONCLUSIONS: The results show that effective PAP treatment has beneficial effects on the blood lipid profile, which enhances sleep efficiency and sleep quality in patients.