Background: Obstructive sleep apnea (OSA) is a breathing disorder that occurs in sleep, which poses many threats more than disturbed sleep. It is associated with major comorbidities. There are insufficient studies in India regarding multiple comorbidities and OSA syndrome. The objective of this studyis to compare the incidence of comorbidities in documented OSA patients with subjects without OSA. Methods: The study was carried out with a total of 274 patients in tertiary-care hospital for a period of 6 months. The study design used was retrospective case–control study. Patient history was taken from the documented records. SPSS package was used for estimating results. Results: Mean age of patients was 55.53±11.37 years. Average apnea–hypopnea index was 45.50±24.51. A total of 110 men and 27 women were seen. The age group of 45–65 years recorded the highest number of OSA patients with a greater severity. The prevalence of hypertension (HT) in case group was 38.4%. When the correlation coefficient was calculated, HT correlated the most with OSA (r=0.513, P=0.01) followed by stroke, hypothyroidism, and coronary artery disease. The least correlation was withdiabetes mellitus (r=0.172, P=0.01)withprevalence of 40.15% in case group. Conclusions: The study showed that prevalence of comorbidities is more in patients with OSA than without OSA.