A method of operating a semiconductor memory device includes, applying a read voltage to a selected word line to which a selected memory cell is coupled and applying a pass voltage to non-selected word lines to which non-selected memory cells are coupled, reading data stored in the selected memory cell by sensing the voltage of a bit line associated with the selected memory cell and the non-selected memory cells, discharging the non-selected word lines, and discharging the selected word line after the non-selected word lines are discharged.