Obesity is a disorder of body weight regulatory systems characterized by an accumulation of excess body fat. World Health Organization recommended that 66% of deaths now occur in developing countries and recognizes obesity as a leading risk factor. Obesity is associated with chronic, low grade, systemic inflammation. The inflammatory state play a causal role in the development of insulin resistance, type 2 diabetes and the metabolic syndrome. This descriptive type of cross sectional study will design to evaluate the relation between obesity with hemoglobin concentration. One hundred obese and 100 normal weight persons from both sexes, aged between 25 to 60 years will be selected from Mymensingh Medical College, Mymensingh and locality from July 2014 to January 2016. Data are collected through a simple questionnaire after informed consent taken. The result was calculated and analyzed by using SPSS (statistical package for social science, version 11.5). Statistical significance of difference between two groups were evaluated by unpaired Student's 't' test. Data were expressed as Mean±SE. P value less than 0.05 was taken as the level of significance. Anthropometric measurements such as height and weight were taken in meter and kilogram respectively. Pulse, systolic and diastolic blood pressure was measured by aneroid sphygmomanometer (ALPK2, Japan), laboratory analysis of hemoglobin was done by Cyanmethemoglobin Method. In this study we found that hemoglobin concentration is significantly increased in both male and female obese persons.