Background: Acromegaly is a rare endocrine disorder; it has an incidence of 4 per million annually and a prevalence of 40 per million. It is due to a growth hormone-secreting pituitary adenoma. Objective: To evaluate the levels of β-arrestin in patients with acromegaly with and without obstructive sleep apnea (OSA). Methods: One hundred and five registered patients with acromegaly at the National Diabetes Center, Mustansiriyah University, were enrolled in the study. Of the 105 patients with acromegaly, 81 have OSA, while the remaining 24 have no OSA. Obstructive sleep apnea affects 81.8% of males and 72% of females. All recruited patients have given oral consent to participate in the study, which was conducted from January to October 2023. Results: Males with OSA had a mean age of 52 years, while those without OSA had a mean age of 46 years. The Epworth sleepiness scale is higher among those with OSA. β-arrestin is higher in males with OSA (6.309 pg/ml), while in females with OSA, it is 6.278 pg/ml. In no OSA group, the β-arrestin level was 3.067 pg/ml, while in those with OSA, it jumped to 6.29 pg/ml. Conclusions: The results showed that β-arrestin was elevated in patients with acromegaly and obstructive sleep apnea versus those without obstructive sleep apnea. OSA is more common in males, particularly when they get older.