A prayer wheel is a Buddhist device consisting of a cylindrical wheel on a spindle, in which a scroll is placed with a mantra (prayer) written hundreds or sometimes thousands of times. The wheel is spun in a clockwise direction (based on the movement of the sun across the sky), allowing with each revolution the accumulation of as much merit as if each of the mantra inscriptions were read aloud separately. The more prayers a wheel holds, the more powerful it is considered to be. Turning the prayer wheels also assists to dissipate negative energy, or bad karma.

Traditionally, Tibetans and Nepalis use prayer wheels to accumulate merit and good karma for themselves, however any excess merit that an individual may gather during a session of use is freely given to all other sentient beings.