An information processing system includes an image forming apparatus and a mobile terminal capable of performing wired or wireless communication with the image forming apparatus. A voice recognition application is installed in the mobile terminal. The image forming apparatus includes a pedestal to which the mobile terminal is attached, a motion sensor that starts operating when the mobile terminal is attached to the pedestal to detect whether a person is coming close, and a CPU that instructs, when it is determined based on a result of the detection that a user has come close to use the image forming apparatus, the mobile terminal to start the voice recognition application or operate the same in the foreground. The mobile terminal includes a voice output section configured to notify a user that the mobile terminal is capable of responding to voice input, when the instruction is received.