Reciprocating saws are saws with a straight blade mounted at the end of a gun-like body. The blade moves back and forth (hence the name "reciprocating"), much like the action of a jigsaw, but reciprocating saws are much more powerful and versatile than jigsaws. if fitted with the correct blade they are able to cut through virtually anything, but make rather rough cuts compared with other types of saws, so they are generally used for demolition work.

Models range widely in power, speed, and features, from less powerful cordless models that are usually shaped like a cordless drill, to high-power, high-speed, corded models like the industry standard Milwaukee Sawzall. Because of the ubiquity of the Sawzall line, this type of saw is generally called a "Sawzall" regardless of its brand or model.