Introduction: Diabetes Mellitus is independent risk factor for pulmonary infections manifesting with serious clinical features, frequent complications, increased morbidity & mortality.Objectives: Determine whether the clinical, radiological findings & causative organisms of pulmonary infections are modified in Diabetes mellitus.Methods: Prospective analytical case control study conducted from June 2016 - june2018 involving 150 Type 2 diabetes & 80 non-diabetic controls selected on basis of simple random sampling. RBS, Chest X-ray, sputum AFB, culture sensitivity were done.Results: Patients in diabetic group had longer duration-of-hospital stay, symptoms like cough, sputum production, breathlessness & fever.Patients in diabetic group had higher incidence of lower zone opacity, cavities & pleural effusion compared to non-diabetics, sputum showed higher positivity rate for gram-negative bacilli & fungal elements, higher incidence of pulmonary tuberculosis & culture showed higher rates of staph-aureus, candida species, klebsiella & pseudomonas which were sensitive to higher antibiotics like imipenem. Diabetic group had more complications like prolonged duration of hospital stay, pleural effusion, respiratory failure, anemia & mortality compared to non-diabetic group.Conclusion: Diabetics had significantly longer duration of symptoms like cough, sputum production, breathlessness & fever compared to non-diabetics. Tachypnea, cyanosis were more in diabetics. Diabetic patients had higher-involvement of lower zones, cavity & pleural effusion on chest x-ray. Gram stain & KOH showed higher incidence of gram negative bacilli and fungal elements. Pulmonary tuberculosis presenting as pneumonia & cavitatory lesions were significantly higher among diabetics compared to non-diabetics, Diabetics had significantly higher incidence of pulmonary infections due to staph. Aureus, klebsiella and pseudomonas, candida species. Diabetic patients had significantly prolonged duration of hospital stay, pleural effusion, sepsis, respiratory failure, anemia & mortality when compared to non-diabetics