Methods and apparatus for determining proper placement of a substrate upon a substrate support in a process chamber are disclosed. In some embodiments, a method for detecting substrate placement in a process chamber includes placing a substrate on a support surface of a substrate support within the process chamber; modifying a pressure within the chamber to create a detection pressure within the chamber; sensing a first temperature of the substrate support; monitoring a thermal response characteristic of the substrate support after placing the substrate on the substrate support; comparing the thermal response characteristic to a predetermined response characteristic; and determining whether the substrate is placed correctly based upon the comparison of the thermal response characteristic to the predetermined response characteristic.