Objective: Present experiment was undertaken to find out the postnatal development (gross) of the duodenum in broiler chicken with regard to their location, shape, size and weight. Materials and Methods: A group of five chickens, each at day 1 (D1), day 7 (D7), day 12 (D12), day 24 (D24) and day 34 (D34), total 5, were killed and their digestive tracts were dissected. After that, samples of duodenum were prepared and the length, width and muscle diameter of duodenum of different ages were recorded. Results: The average length of duodenum were significantly higher in broilers at day 34(30.55cm) than that at day 24(28.12cm), day 12(19.50cm), day 7(17.25cm) and day 1(14.95cm). On the other hand, the width were significantly higher in broilers at day 34(7.1mm) than that at day 24(5.25mm), day 12(4.70mm), day 7(4.35mm) and day 1(2.75mm). In diameter of the muscle of duodenum also maintain this order. Conclusion: Hence, it can be concluded that, length, width and muscle diameter of duodenum might be increased with the age of broiler.