An image printing system for an endoscope includes a printer, a print commander, a printer-information memory, a timer, and an image data memory. The printer prints an image, and the print commander commands the printer to print the image. The printer-information memory stores printer-information, including time-information that represents a required-time-period for the printer to print an image on a substrate. The timer measures an elapsed time from when the printer starts printing the image. The image data memory stores image data of the image commanded by the print commander until the required-time-period elapses. If the elapsed time from when the printer starts printing the image until when the print commander commands the printer to print a new image is shorter than the required-time-period, the printer can print the new image based on image data of the new image stored in the image data memory.