Spleen is a haemo-lymph organ and belongs to the reticuloendothelial system of human body, develops from mesodermal proliferation between the two leaves of dorsal mesogastrium. The microscopic structure of spleen is variable depending on the developmental stage of the organ, and the age and immune status of the individual. In our country, we depend on foreign data which came from the subjects of different races and from the individuals under different geographic conditions. So the study was carried out to minimize the dependency on foreign standards and to identify the diameter of white pulp in different age and sex of the Bangladeshi individuals with a view to establish local data bank related to spleen of Bangladeshi people. This cross-sectional descriptive study was performed on 65 postmortem human spleens (34 of male and 31 of female) to find out the number and diameter of white pulp of spleen of Bangladeshi people by purposive sampling technique. And done in Autopsy laboratory of the Department of Forensic Medicine of Mymensingh Medical College, Bangladesh from 16th October 2016 to 15th January 2017. The samples were divided into three age groups including Group A (5-20 years), Group B (21-40 years) and Group C (41-60 years). Dissection was performed according to standard autopsy techniques. For statistical analysis, unpaired student 't' test was done. The mean±SD number of white pulp of male spleen was greater than female spleen in Group A, B and C but mean±SD diameter of white pulp of female spleen was found greater than male spleen in all groups. Comparison of number of white pulp between sexes showed that statistically there was no significant difference within all the age groups at p>0.05 level. No age change was evident in diameter of white pulp but in between sexes, diameter is greater in females than males. Mean difference of diameter of white pulp between sexes showed no significant difference within the age groups at p>0.05.