Introduction: Chronic rhinosinusitis (CRS) is an upper airway inflammatory disorder lasting more than 12 weeks. It is a significant health burden affecting 5 to 12 % of general population and is one of most common cause for loss of workforce in society. Bacterial pathogens, both aerobes and anaerobes are implicated to most of the cases of CRS including altered natural flora, mucociliary dysfunction, inflammation and oedema of sinus mucosa leading to various symptoms of CRS. Symptomatological association of microbiota is needed so as to target the treatment and prevent undue use of antibiotics. 

Aim & Objective: To identify type of predominant bacterial flora in maxillary sinusitis and to associate the symptomatology of chronic maxillary rhinosinusitis with causative bacteria. 

Methodology: A prospective observational study was conducted in Department of ENT in association with Department of Microbiology BRD Medical College Gorakhpur Between January 1st 2019 to December 31st 2019. All patients between 15 years to 70 years of age irrespective of gender with symptoms of chronic maxillary sinusitis more than 12 weeks were included in the study.

Result & Observation: The most common etiological agent associated with CRS in this study was observed as Staphylococcus aureus followed by Pseudomonas aeruginosa. Headache followed by nasal blockage were the most common symptoms exhibit by patients with CRS.  

Conclusion: Chronic maxillary sinusitis is a multifactorial entity. Knowledge of microbiota and their association with specific symptoms paves a path to targeted antimicrobial treatment. This causal association is useful in predicting the course the treatment but a study with bigger sample size is needed to establish the causality.