A study was carried out to investigate the nesting behavior of giant honeybees Apis dorsata in Terai, Nepal from September 2002 to March 2004. More than five hundred nesting sites of A. dorsata colonies including old and new located at different parts of the country were visited and studied for the nesting behavior. Combs of brood and honey were collected from different nesting sites of A. dorsata and studied. A. dorsata bees built single comb as nest to rear brood and store food. The bees preferred more to build their nest on tall and safe buildings followed by on trees and rarely on rocks. They gave highest preference to the strong cemented water tank and then to residential buildings having flat slab made out of bricks, iron and cement for making their nests. In absence of such buildings, the bees built the nests on the strong live big branches of silk cotton trees (Bombax ceiba) and rarely on other tree species. They never built the nests on an old and weak buildings and dead trees that were not strong enough to support the load of the nest. The bees built the single comb at an elevation of 2m to 50m from ground level towards the sunny, opened and undisturbed area. Highest preference was given to the same spot of previous year nest to rebuild the nest. The bees never rebuilt their nests on the spot of previous nest if it was burnt on fire or treated with chemical(s) or washed or painted with paints. Several colonies lived friendly together very close to each other sometimes touching each other’s nest. The size of the nest varied from 5cm to 150cm in length, 4cm to 15cm in breath and 10cm to 50cm in height with a shape of mostly conical at the beginning and elliptical with the growth of comb. The elliptical shape of the comb is plain, bent, curved or angular depending upon the nature of the nesting sites. Bees did not rebuild the brood comb after cutting. Honey and pollen is stored at one of the upper most corner of the nest providing beneath more area for brood production except at the center in one nest. Worker and drone brood are reared on the same size of hexagonal cells raised over the thick and strong foundation. The length of each side of worker and drone cell is 3.0mm with a depth of 15mm. The shape of the queen cell is round with a diameter of 9.0mm at the top. The wall of queen cell is thicker (up to 2mm) then that of worker cells (>0.5mm). Honey and pollen stores are the combination of horizontally extended long, soft and thin cylindrical cells measuring up to 10cm in length built to both sides on the thin foundation. The cells at the comb attachment point are very hard to press used to store pollen and honey measuring up to 5cm in length and 1mm in thickness. The giant honey bee A. dorsata has specific preferences for selecting the site to build the nest and live many colonies friendly together. They leave the nest and fly away in search of food and better nesting sites when food becomes shortage or weather becomes unfavorable or are disturbed frequently by enemies. Several colonies of A. dorsata can be attracted every year to manmade buildings and retained for longer duration for the production of honey and bee bread, bee wax and various other purposes through better management.