Abstract: A rebar tying system including a chassis with a central opening that passes from top to bottom of the chassis, a plurality of driven wheels coupled to the chassis and configured to propel the rebar tying system bidirectionally over a rebar mat, a plurality of foot members coupled to the chassis and configured to selectively move the rebar tying system in a lateral direction relative the bidirectional wheel propelled movement, and a rebar tying gun configured to be selectively positionable both horizontally and vertically in the central opening to perform rebar tying operations.