A tube printer is used for printing information on an interior surface of a tube. The tube printer includes housing, an ink wheel assembly and a print wheel. The housing having at least two side members interconnected by a top plate extending there between and including spring biased guide wheels that cooperatively center the housing within the tube. An operating handle is operatively attached to an end of the housing to provide a means to push and pull the tube printer within the tube. The ink wheel assembly is operatively positioned between the side members of the housing and the print wheel is operatively positioned between the side members of the housing and adjacent the ink wheel and includes a raised surface containing the information to be printed on the interior surface of the tube.