Community-acquired pneumonia (CAP) is a common presentation with an acute infection of the pulmonary parenchyma occurring in the community level. Despite the availability of potent antibiotics, it remains as a serious illness with significant morbidity and mortality in both developed and developing countries. This study was undertaken to determine the relation between serum Albumin and severity of CAP. This was a cross sectional descriptive study which was carried out in the Department of Medicine of Mymensingh Medical College Hospital (MMCH), Bangladesh from July 2019 to December 2019. The sample size was 67. Purposive sampling technique was employed. Patients of community acquired pneumonia (CAP), aged ≥14 years of both sex with recently developed radiological pulmonary shadowing with compatible clinical symptoms and signs were included. Patients who were chronically immunosuppressed, with chronic starvation, advanced liver disease or chronic kidney disease with or without receiving haemodialysis were excluded. Data analysis was done by SPSS software for Windows (version 23.0). The mean age 65.7±15.3 years, majority 13(19.4%) patients had chronic lung disease, 12(17.9%) had diabetes mellitus, 9(13.4%) had heart failure, 6(9.0%) had cerebrovascular disease, 6(9.0%) had neoplastic disease and 5(7.5%) had chronic renal failure. Majority 22(32.8%) patients had CURB-65 score 3, out of which 12(54.5%) had albumin level <20g/l, 9(40.9%) had albumin level 20.0-24.9g/l and 1(4.5%) had albumin level 25-29g/l. 17(25.4%) had score 4-5 out of which 10(58.8%) had albumin level <20g/l and 7(41.2%) had albumin level 20.0-24.9g/l, 15(22.4%) had score 2 and 13(19.4%) had score 0-1. Negative significant correction (r=-0.782; p=0.001) was found between CURB-65 score and albumin level. Significant number of patients with severe CAP show low serum albumin level at admission which is statistically significant when compared with CURB-65 score. Thus hypoalbuminaemia may be a good marker of severity of patients with CAP.