In India, the hoolock gibbon, Hoolock hoolock, is found only in a small part in the northeast, south of the Brahmaputra River and east of the Dibang River. This article describes its distribution, habitat and conservation and also compares its relative status over the past 15 years in Karbi Anglong, the largest district of Assam in India. The hoolock gibbon still occurs over a large part of the district but in depleted numbers. It has been recorded from altitudes of less than 100 m to above 1,300 m. Hoolocks have become rarer due to habitat loss and hunting and, except for a few protected areas and larger reserved forests, they are found in scattered groups, where they may not survive for long. Karbi Anglong has the largest known habitat and estimated population of the species in Assam. A rough population estimate indicates that the total numbers of hoolock gibbons today could be between 2,400 and 3,200. This can be compared to an estimate in 1991–1992 of 3,500–4,800. The hoolock gibbon is protected by law and occurs in all the five protected areas and in at least 20 reserved forests and 14 proposed reserved forests in the district. Of these, its continued presence is doubtful in at least four reserved forests and one proposed reserved forest. The creation of further protected areas, adequate protection of existing protected areas, control of jhum cultivation and poaching, and awareness and involvement of churches and village headmen in conservation are recommended.