Background: Although significant improvement has been achieved in terms of antibiotic care, otitis media (OM) continues to be a worldwide health problem that may develop serious complications. This study aimed to detect the growth of organisms and to find out the most susceptible factors related to OM among the Iraqi population. Methods: A prospective cross-sectional study was conducted at the out-patient department (OPD) of Ear, Nose, and Throat (ENT) at the Baquba teaching hospital at the Faculty of medicine, Diyala University from November 2017 to March 2018. A total of 300 ear samples collected from 87 (29.0%) patients of acute otitis media (AOM), 104 (34.7%) patients of otitis media with effusion (OME), and 109 (36.3%) patients of chronic otitis media (COM). Standard microbiological procedures were recruited to investigate the samples using aerobic and anaerobic culture methods. Results: The highest incidence of OM 218 (72.7%) was observed among the age group of fewer than ten years old. The most common bacteria isolated were Pseudomonas aeruginosa (35.0%), Staphylococcus aureus (25.0%), Proteus spp. (24.0%), Escherichia coli (7.0%), Streptococcus pneumonia (6.0%), Klebsiella pneumonia (2.0%) and Streptococcus pyogenes (1.0%). It was found that upper respiratory infection (URTI), adenoid inflammation with (URTI), adenoid inflammation, the practices of complementary and alternative medicine (CAM), and the accident or trauma are the main factors related to OM in about (42.0%), (31.0%), (11.0%), (10.0%) and (6.0%) of cases respectively. Conclusion: Our findings suggest that OM was effectively related to URTI and adenoid inflammation with (URTI) in about 73.0% of cases. More attention should be given to early diagnosis and treatment of URTI before progressing to undesirable OM.