Brhat Trayi

The Bṛhat-Trayī, literally translated as "The Great Triad (Of Compositions)", refers to three early Sanskrit encyclopaedias of medicine, which are the core texts of the indigenous Indian medical system of Ayurveda. These are contrasted with the Laghu-Trayī or the "lesser triad", a secondary set of later authoritative compositions.

This classification was first devised probably at some time in the early twentieth century, although its earliest use has not yet (2022) been identified. The classification is not known to Sanskrit authors. It is part of the creation of a formal canon for ayurvedic literature.

There are older medical encyclopaedias that are not included in the Bṛhat-Trayī, for example the Bheḷa-saṃhitā.