This invention is directed to a printing apparatus and printing medium roll-up state discrimination method of printing using a rolled printing medium while reliably rolling up the printing medium after printing and accurately detecting a roll-up error. This printing apparatus prints on a rolled printing medium, rolls it up in accordance with the discharge operation of the printing medium after printing, and optically detects the roll-up state of the printing medium upon roll-up. The printing apparatus discriminates an abnormality in the roll-up state of the printing medium on the basis of the detection result.