Abstract: The different parts of digestive system of one-day old, 30 days, 90 days and 180 days old deshi chickens were taken in fresh state and stained with hematoxylin and eosin (H and E). The aim of this study was to investigate the distribution of lymphocytes in the different histological layers of the digestive tract of deshi chicken at the different ages of postnatal growth and development. In the present study the Intraepithelial Lymphocytes (IELs) were not abundant in the upper segments of the digestive tract (oesophagus, crop, proventriculus and gizzard), however these immunocompetent cells were abundantly found in the distal part of the digestive tract (duodenum, jejunum, Meckel`s diverticulum, ileum, caecum, cecal tonsil and colorectum). The population of IELs in the distal part of the tract were found higher from day 90 to day 180 of postnatal period of development, however in the jejunum, caecum and ceacal tosil the frequency were found abundant at day old ages only. The lamina propria of the different segments of digestive tract contain isolatory and diffuse lymphocytes. In addition to these isolatory lymphatic nodules and aggregated lymphatic nodules were present and there were higher in frequency at day 90 and at day 180 of postnatal ages. The lymphocytes were also distributed scatteredly in the submucosa and tunica muscularis in all the stages of development. These results suggest that the development of the population of lymphocytes in the postnatal period vary with the different segments of the digestive tract concerned and aging of chicken of Bangladesh.