Albizia lebbeck benth, known as Shirisha in Ayurveda is an important medicinal plant belonging to the family Fabaceae (Formerly Leguminosae) and a member of subfamily Mimosaceae. The plant is useful in many disease conditions and is known for its anti-inflammatory, anti-histaminic, anti-anaphylactic, anti-asthmatic and anti-microbial etc. activities. The pharmacognostical study of flower, leaf, and stem bark of this plant are reported but heartwood is not available in any of the works including API (Ayurvedic Pharmacopoeia of India). Considering this an attempt has been made for first time to evaluate correct and easy identification and authentication of drug. The present study deals with morphology, macro and microscopic studies, preliminary physico-chemical and phytochemical analysis of heartwood of Shirisha.