<p>Obstructive sleep apnea (OSA), characterized by repeatedly collapse of upper airway while sleeping, is a common disease; estimated to have a prevalence of 57% in adults. Headache is a common neurological symptom and can be bothersome. A meta-analysis found that 33% of patients with OSA may have headaches. There is limited data on risk factors for having headache in patients with OSA. This study aimed to find risk factors or phenotypes of headache in patients with OSA. This was a retrospective analytical study. The inclusion criteria were adult patients with age of 18 years or over and diagnosed as OSA by polysomnography. The primary outcome of this study was a symptom of headache. Predictors for headache in patients with OSA were executed by stepwise method of multivariable logistic regression analysis. There were 213 patients with OSA met the study criteria. Of those, 52 patients (24.41%) had headache. The most common type of headache was tension type (27 patients; 51.92%), followed by non-specific type (22 patients; 42.31%), and migraine type (3 patients; 5.77%). There were four significant factors including dyspnea, fatigue, dizziness, and macroglossia. Dyspnea had the highest adjusted odds ratio at 3.29 (95% confidence interval of 1.25, 8.54), while macroglossia had the lowest adjusted odds ratio at 2.10 (95% confidence interval of 1.01, 4.43). Patients with OSA who had the following phenotypes of dyspnea, fatigue, dizziness, and macroglossia may have a higher chance of having headache.</p>