Capnomancy is also known as Libanomancy, it is a form of divination by interpreting the movement of smoke rising from a fire, especially smoke from sacrificial offerings, which augured well if it rose lightly from the altar, and ascended straight to the clouds; but the opposite if it hung about.

Another method was to cast some jasmine, laurel leaves, granulated incense, or poppy seeds upon burning coals to observe the smoke behavior and sniff it, and then draw omens from the alleged findings. A third method yet was to breath the smoke from a sacrificial fire.

Capnomancy (Greek: kapnos, smoke; manteia, divination) is a form of Pyromancy, and is believed to have originated in ancient Babylon, where on certain sacred days they used to burn cedar branches or shavings to draw omens from the patterns of the smoke. The Druids were also very skilled in the art of capnomancy, using the smoke generated by the burning of humans and animals on a sacrificial altar.

The term capnomancy was also used of divination by means of a trance induced by ingesting smoke from a specially prepared drug.