According to one embodiment, a tablet printing apparatus includes: a first conveyor conveying a tablet while holding a other surface of the tablet; a second conveyor conveying the tablet transferred from the first conveyor while holding a one surface of the tablet; a first print head performing printing on the one surface of the tablet; a second print head performing printing on the other surface of the tablet; a first detection mechanism detecting the one surface of the tablet; a second detection mechanism detecting the other surface of the tablet; and a controller sending a printing instruction to the first and the second print heads based on information related to the state of a split line included in detection information on the one surface of the tablet or detection information on the other surface of the tablet.