Serum proteins are an important indicator of the nutritional status in an individual. There is a worldwide prevalence of both undernourishment and obesity. It has been suggested that low Body Mass Index (BMI) is associated with a decrease in serum protein levels predisposing them to other illnesses. Overweight and obese individuals carry risk for various other non-communicable diseases. To compare the serum protein levels in underweight, overweight and obese individuals with that of normal body mass index individuals. This prospective study was conducted in subjects who attended the master health checkup clinic of PSG hospitals. Subjects in the age group of 20-50 years were selected. Their serum proteins and BMI was measured. Twenty subjects each of underweight, normal, overweight and obese individuals were selected, categorized and compared. The serum protein level of normal individuals (Group I) was compared with underweight (Group II), overweight (Group III) and obese subjects (Group IV) by one-way ANOVA analysis. The mean serum total proteins in gm/dl in group I controls was 7.555±0.37 compared to Group II (underweight) which was 7.295±0.419. Low BMI was found to be associated with a decrease in serum protein level which was not statistically significant. Elevated BMI as in overweight and obese subjects showed no significant alterations in serum protein levels with p >0.05 and the changes were found to be independent of the body mass index. Underweight individuals showed a decrease in serum protein levels whereas there were no significant changes in the serum protein levels in overweight and obese individuals.