Introduction About one-half of patients who have essential hypertension have obstructive sleep apnea (OSA), and about one-half of patients who have obstructive sleep apnea have essential hypertension. OSA can cause even resistant hypertension if left untreated. These two entities often co-exist and are seen as a continuum of the same process. Eighty percent to 90% of OSA cases are undiagnosed mostly because of a lack of awareness. Material and methods This was a cross-sectional study done over a period of one year in a tertiary care hospital. After taking informed consent, 179 hypertensive patients of >18 years were included in the study. All patients were screened for OSA by the STOP-BANG questionnaire. Patients having scores of ≥3 were subjected to overnight polysomnography to confirm the diagnosis of OSA (AHI ≥5). Patients with a STOP-BANG score ≤2 or score ≥3 with AHI <5, were considered non-OSA. Results More than half (53.1%) of the patients enrolled in the study had OSA. Their age ranged from 18 to 78 years and the mean age was 52.07±11.40 years. The mean age of OSA cases was found to be slightly higher than that of non-OSA. The majority of OSA cases were males (73.7%). There was an increase in the prevalence, as well as the severity of OSA, with an increase in BMI. Most of the cases had snoring and a history of tiredness. Triglyceride (TG) and low-density lipoprotein (LDL) levels of the OSA group were found to be significantly higher and high-density lipoprotein (HDL) levels were significantly lower than that of the non-OSA group. Conclusion More than half of our hypertensive patients had OSA. These two conditions often co-exist and are known as a dangerous pair. Physicians ought to have increased suspicion for early diagnosis and treatment to improve cardiovascular outcomes, reduce road traffic accidents, and improve quality of life.