Background: Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder characterized by repeated upper airway obstruction during sleep. While respiratory pauses followed by loud snoring and daytime sleepiness are the main symptoms of OSAS, most of the patients complain from sleep disruption, mood disturbance, irritability and poor quality of life. Depression and anxiety can be corelated to the different subtypes of insomnia associated with OSAS. Subjects and Methods: Cases recruited from outpatient clinic in pulmonary department in Mediclinic hospital in Abu Dhabi, UAE. 60 cases collected over 6 months, diagnosed to have obstructive sleep apnea syndrome using. The American Academy of Sleep Medicine (AASM, 2014). After which the subjected to scales to diagnose possible comorbid anxiety and depression in addition to scale to determine presence and absence of insomnia with its type in every case. Results: This study shows significantly higher prevalence of insomnia among OSAS group versus control. Result showed higher Hamilton  epression and anxiety scores in OSAS- insomnia group more than OSAS without insomnia with significant positive correlation between initial insomnia and Hamilton anxiety scores and between maintenance insomnia and Hamilton depression scores. Conclusions: We conclude that depression and anxiety is a common comorbidity with OSAS and that finding was higher in OSAS with insomnia patient group more than those without insomnia. Which suggested that there is an association between OSAS-insomnia and overall patient quality of life.