Self-heating effects became more prominent with the introduction of the modern devices like FD-SOI and low thermal conductivity materials such as SiO2. Consequently, the temperature rise of a device due to its self-heating is pronounced more as the gate lengths shrink and the power density values increase. In analog design, one of the main drawbacks of elevated temperature is the deterioration of the thermal noise performance. For observing the thermal noise performance of FD-SOI MOSFETs, a thermal model for the device self-heating is used. The influence of self-heating on the thermal noise is examined by activating and inactivating the self-heating thermal model and comparing the results. It is shown that self-heating can deteriorate the thermal noise current (up to 18%) and the input referred thermal noise voltage (up to 37%) significantly for short channel FD-SOI devices.