An electrothermal annealing (ETA) was applied to improve the ON-state current (I-ON) of an exfoliated MOS(2 )field-effect transistor (FET). The ETA uses localized Joule heat generated by current flowing through the source and drain of the device. Process-induced contaminants in both the MOS(2 )channel and MOS2-metal junctions were reduced. Electrical characterization, including the extraction of mobility and parasitic resistance, was performed to analyze the annealing effects. Numerical thermal simulations were also performed to provide insight on parameters to optimize the ETA process since the MOS2 flakes have diverse sizes and asymmetric shapes in the exfoliation-based MOS2 FETs.