The Agasthyamala Biosphere Reserve is one of the premium biosphere reserves in India and is covering the districts of Kollam, Thiruvananthapuram, Pathanamthitta, Kanyakumari and Thirunelveli, in Tamil Nadu and Kerala. The reserve was established in the year 2001 and is jointly being run and managed by the Ministry of Environment & Forests, Government of India; the Tamil Nadu Forest Department and the Kerala Forest and Wildlife Department. It has a total area of 3,500.36 sq. km., out of which 1828 sq. km. is in Kerala and 1672.36 sq. km. is in Tamil Nadu. Along with the Western Ghats, and the Agasthyamalai Sub-Cluster, the reserve is under consideration by the UNESCO World Heritage Committee for selection as a World Heritage Site.

The location of the Agasthyamala Biosphere Reserve is almost 1868 m high in the Agastya Malai Mountain and it also straddles the border of Kollam and Thiruvananthapuram Districts in Kerala and Thirunelveli and Kanyakumari Districts in Tamil Nadu, South India. This is situated at the southern end of the Western Ghats. The reserve comprises the wildlife sanctuaries like Neyyar, Peppara and Shendurney. Their adjoining areas like Achencoil, Thenmala, Konni, Punalur, Thiruvananthapuram Divisions and Agasthyavanam Special Division in Kerala, are also include in the biosphere reserve.

The Agasthyamala Biosphere Reserve includes several Indian Ecoregions like the South Western Ghats moist deciduous forests, South Western Ghats montane rain forests and Shola. The reserve is home to a large number of 2,000 varieties of medicinal plants, out of which at least 50 are identified as rare and endangered species. Apart from the medicinal plants, some rare animals like the Tiger, Asian Elephant, and Nilgiri Tahr are also found in this reserve. The reserve provides habitat to one of the oldest surviving ancient tribes in the world, Kanikaran, as well. The day-to-day activities of the Agasthyamala Biosphere Reserve is being supervised and monitored by a local committee and a state level Biosphere Management Committee. Both the committees co-ordinate the activities of various departments in the reserve area and ensure its scientific management. The activities are coordinated in accordance with the guidelines of the Indian Ministry of Environment and Forests.