A projection adjustment program which causes a computer to execute a process relating to adjustment of projection operations of a plurality of projection devices configured to perform position measurement and projection on a target object in a projection system including the plurality of projection devices. The process includes: causing a projection device to project measurement light onto the target object; causing an image capture device to receive reflection light of the measurement light, the reflection light being reflected from the target object; judging a connection relationship of a projection range of the projection device on a basis of the received reflection light of the measurement light; executing a process of the judging of the connection relationship on all processing target projection devices; generating projection position information indicating a connection relationship between projection ranges of the respective projection devices of the projection system; and displaying the generated projection position information on a display.