Introduction: Noise-induced hearing loss is a serious health issue that affects people all over the world. Occupational noise-induced hearing loss (ONIHL) is one of the commonest occupational diseases. Several factors have been revealed to produce hearing loss including diabetes mellitus (DM). Aim of Work: To study the relation between type II DM and ONIHL. Materials and Methods: A total of 1292 workers from 3 companies, occupationally exposed to noise, were categorized into normal and hearing impairment groups by pure tone audiometry (PTA). The studied group was subjected to a specially designed detailed questionnaire about noise exposure at work and hearing problems. Blood pressure, fasting blood sugar, serum urea, creatinine, and glycated hemoglobin (HbA1c) were measured. Body mass index was calculated. Results: DM was more frequent among workers with NIHL (13.2%) than those without (4.8%). Diabetic workers tended to be significantly older than the non-diabetics (50.6 ±7.2 compared with 40.9 ± 9.6 years, p < 0.001), they also spend longer time exposed to noise at work (9.2 ± 6.6 years compared with 6.6 ± 5.7 years, p= 0.002). Both systolic and diastolic blood pressures were significantly higher among diabetic than non-diabetic workers. Diabetic workers had a higher loss of hearing levels at all studied frequencies. By multiple logistic regression analysis, diabetes mellitus, noise exposure years, and age were significant predictors of NIHL. Glycated hemoglobin (HbA1c) had a significant positive correlation with the overall hearing loss. Conclusion and Recommendations: Diabetes mellitus increase the risk of developing noise induced hearing loss among workers exposed to noise at the workplace. Diabetic workers in noisy occupations should undergo frequent audiological assessments, should have easier access to healthcare facilities and their blood glucose levels checked regularly including HbA1c testing.