A woodblock is essentially a small piece of slit drum made from a single piece of wood and used as a percussion instrument. It is struck with a stick, making a characteristically percussive sound.

East Asian musics use a variety of wood blocks ranging from small hand-held instruments to enormous (often immovable) temple blocks which may be sounded by swinging a large log against them. Log drums made from hollowed logs, and slit drums made from bamboo, are used in Africa and the Pacific Islands.

The muyu (simplified Chinese: 木鱼; traditional Chinese: 木魚; pinyin: mùyú) is a rounded woodblock carved in the shape of a fish and struck with a wooden stick. It is made in various sizes and is often used in Buddhist chanting, in China as well as in other Asian nations including Japan, Korea, and Vietnam. Also in China, a small, rectangular, high-pitched wood block called bangzi (梆子) is used. In Vietnam, a slit drum called song lang is widely used.

The orchestral wood-block instrument of the West is generally made from teak or another hardwood. The dimensions of this instrument vary considerably, although it is always a rectangular block of wood with one or sometimes two longitudinal cavities. It is played by striking it with a stick.