Background: In Siddha System of Medicine, Meliaceae members such as Azadirachta indica A. Juss., Melia azedarach L., Aglaia odorata Lour. etc., have been used as an ingredient in several formulations owing to their high potential therapeutic values. In recent decades, another member of this family Swietenia macrophylla King (broad leaved mahogany) has drawn a great attention by its commercial and medicinal values. The medicinal properties of mahoganies have been explored thoroughly by the distinguished researchers worldwide that urges to make the identification key to differentiate them from the adulterants. Since the micro-morphological characters are the key in the identification of herbal drugs, the present study was intended to explore macro-micro and HPTLC/TLC characteristic features of leaves, stem bark and seeds of broad-leaved mahogany (S. macrophylla) and a comparison has been carried out with respect to the earlier studies of Indian mahogany (S. mahagoni). Materials and Methods: Plant parts such as leaves, stem bark and fruits are collected from Periyaputhur, Salem District, and Tamil Nadu. The macro-micro observations were made using standard protocols. Total ethanolic extracts of the plant parts were subjected to HPTLC studies too. Results: Microscopic observation of transverse section and powder microscopy of leaves showed the presence of anomocytic stomata, prismatic crystals, crystal fibers, starch granules, spiral vessels etc. The transverse section of the stem bark showed the cork, lenticels, stone cells, cortex with plenty of starch etc. Microscopic observation of the seed wing and cotyledons shows the presence of starchy mesotesta, pitted fibres, oil globules, crystal fibres and stone cells. Conclusion: In the present study, micro-macroscopic characteristic features of stem bark, leaves and seeds of S. macrophylla King (broad leaved mahogany) has been carried out and a comparative account with S. mahagoni (L.) Jacq., another Meliaceae members used in the traditional medicinal system of Siddha is been discussed briefly. HPTLC fingerprint obtained in the study will help in chemical identification of the plant materials.