A radiation imaging system includes a portable electronic cassette having a first cable that includes at least one of a signal line and a power line and is provided with a first connector for connecting to another connector, the electronic cassette being configured to acquire an image based on radiation transmitted through an object a controller having a second cable that includes at least one of a signal line and a power line and is provided with a second connector for connecting to the first connector, the controller being configured to control an imaging operation of the electronic cassette via these cables and a patient platform having an electronic cassette-housing unit in which the electronic cassette can be installed and a connector holding unit in which the second connector can be fixedly fitted. Here, the first connector has a lock/unlock operation unit configured to detachably connect to the second connector.
