Introduction: Hearing loss is a debilitating condition that even mild degrees can disrupt speech processing, communication and limit social interaction. The prevalence of hearing loss and its causes in various age and people groups is different. The aim of this study was conducted to determine the frequency of hearing loss and related factors in patients referred to audiology Clinic of Ghaem Hospital in Mashhad from October 2017 to April 2018. Materials and Methods: This cross-sectional study was performed on 493 people referred to Audiology Clinic of Ghaem Hospital in Mashhad. The cause of referring and family history and related diseases was obtained by a questionnaire and then compared with the results of their tympanometry and audiometry tests. The results were obtained using descriptive statistics and Pearson correlation coefficient. Results: Average age of participants were 41. 2 (± 18. 96) years old and 342 out 493 (69/4%) had hearing loss. 79. 8% men and 62. 6% of women had hearing loss. Sensorineural hearing loss was the most common type of hearing loss (35. 2% of all patients). The Otitis media was the most common cause of hearing loss among patients with hearing impairment (10. 7%). Also, there was a significant relationship between aging and degree of hearing loss. Conclusion: According to this results, hearing loss are frequent among Referents of Audiology Clinic. Some causes of hearing loss, such as infections, noise exposure, and Ototoxic drugs can be controlled, Therefore, preventive health care and appropriate treatments can be helpful in reducing the risk of hearing loss.