Abstract: A pipe perforating machine consisting of an arbor beam over which the pipe to be perforated is moved axially, the beam carrying at its free end a radially extendable die which when extended cooperates with an external die to punch a perforation in the pipe wall, and automatic control mechanism operable once energized to move the pipe axially so that a row of perforations are formed therein, return it to its starting position, index it angularly relative to the dies, advance the pipe to punch another row of perforations, repeating the process until the desired number of rows of perforations have been punched, and finally return the pipe to its starting position, where it may easily be removed and replaced with another pipe, and shut the machine off.